gh-127082: Replace "Windows only" with the availability: Windows in ctypes doc (#127099)

Doc/library/ctypes.rst

@@ -1413,13 +1413,15 @@ way is to instantiate one of the following classes:
 
 .. class:: OleDLL(name, mode=DEFAULT_MODE, handle=None, use_errno=False, use_last_error=False, winmode=None)
 
-   Windows only: Instances of this class represent loaded shared libraries,
+   Instances of this class represent loaded shared libraries,
    functions in these libraries use the ``stdcall`` calling convention, and are
    assumed to return the windows specific :class:`HRESULT` code.  :class:`HRESULT`
    values contain information specifying whether the function call failed or
    succeeded, together with additional error code.  If the return value signals a
    failure, an :class:`OSError` is automatically raised.
 
+   .. availability:: Windows
+
    .. versionchanged:: 3.3
       :exc:`WindowsError` used to be raised,
       which is now an alias of :exc:`OSError`.
@@ -1431,14 +1433,17 @@ way is to instantiate one of the following classes:
 
 .. class:: WinDLL(name, mode=DEFAULT_MODE, handle=None, use_errno=False, use_last_error=False, winmode=None)
 
-   Windows only: Instances of this class represent loaded shared libraries,
+   Instances of this class represent loaded shared libraries,
    functions in these libraries use the ``stdcall`` calling convention, and are
    assumed to return :c:expr:`int` by default.
 
+   .. availability:: Windows
+
    .. versionchanged:: 3.12
 
       The *name* parameter can now be a :term:`path-like object`.
 
+
 The Python :term:`global interpreter lock` is released before calling any
 function exported by these libraries, and reacquired afterwards.
 
@@ -1574,13 +1579,17 @@ These prefabricated library loaders are available:
 .. data:: windll
    :noindex:
 
-   Windows only: Creates :class:`WinDLL` instances.
+   Creates :class:`WinDLL` instances.
+
+   .. availability:: Windows
 
 
 .. data:: oledll
    :noindex:
 
-   Windows only: Creates :class:`OleDLL` instances.
+   Creates :class:`OleDLL` instances.
+
+   .. availability:: Windows
 
 
 .. data:: pydll
@@ -1746,11 +1755,13 @@ See :ref:`ctypes-callback-functions` for examples.
 
 .. function:: WINFUNCTYPE(restype, *argtypes, use_errno=False, use_last_error=False)
 
-   Windows only: The returned function prototype creates functions that use the
+   The returned function prototype creates functions that use the
    ``stdcall`` calling convention.  The function will
    release the GIL during the call.  *use_errno* and *use_last_error* have the
    same meaning as above.
 
+   .. availability:: Windows
+
 
 .. function:: PYFUNCTYPE(restype, *argtypes)
 
@@ -1981,17 +1992,21 @@ Utility functions
 
 .. function:: DllCanUnloadNow()
 
-   Windows only: This function is a hook which allows implementing in-process
+   This function is a hook which allows implementing in-process
    COM servers with ctypes.  It is called from the DllCanUnloadNow function that
    the _ctypes extension dll exports.
 
+   .. availability:: Windows
+
 
 .. function:: DllGetClassObject()
 
-   Windows only: This function is a hook which allows implementing in-process
+   This function is a hook which allows implementing in-process
    COM servers with ctypes.  It is called from the DllGetClassObject function
    that the ``_ctypes`` extension dll exports.
 
+   .. availability:: Windows
+
 
 .. function:: find_library(name)
    :module: ctypes.util
@@ -2007,7 +2022,7 @@ Utility functions
 .. function:: find_msvcrt()
    :module: ctypes.util
 
-   Windows only: return the filename of the VC runtime library used by Python,
+   Returns the filename of the VC runtime library used by Python,
    and by the extension modules.  If the name of the library cannot be
    determined, ``None`` is returned.
 
@@ -2015,20 +2030,27 @@ Utility functions
    with a call to the ``free(void *)``, it is important that you use the
    function in the same library that allocated the memory.
 
+   .. availability:: Windows
+
 
 .. function:: FormatError([code])
 
-   Windows only: Returns a textual description of the error code *code*.  If no
+   Returns a textual description of the error code *code*.  If no
    error code is specified, the last error code is used by calling the Windows
    api function GetLastError.
 
+   .. availability:: Windows
+
 
 .. function:: GetLastError()
 
-   Windows only: Returns the last error code set by Windows in the calling thread.
+   Returns the last error code set by Windows in the calling thread.
    This function calls the Windows ``GetLastError()`` function directly,
    it does not return the ctypes-private copy of the error code.
 
+   .. availability:: Windows
+
+
 .. function:: get_errno()
 
    Returns the current value of the ctypes-private copy of the system
@@ -2038,11 +2060,14 @@ Utility functions
 
 .. function:: get_last_error()
 
-   Windows only: returns the current value of the ctypes-private copy of the system
+   Returns the current value of the ctypes-private copy of the system
    :data:`!LastError` variable in the calling thread.
 
+   .. availability:: Windows
+
    .. audit-event:: ctypes.get_last_error "" ctypes.get_last_error
 
+
 .. function:: memmove(dst, src, count)
 
    Same as the standard C memmove library function: copies *count* bytes from
@@ -2091,10 +2116,12 @@ Utility functions
 
 .. function:: set_last_error(value)
 
-   Windows only: set the current value of the ctypes-private copy of the system
+   Sets the current value of the ctypes-private copy of the system
    :data:`!LastError` variable in the calling thread to *value* and return the
    previous value.
 
+   .. availability:: Windows
+
    .. audit-event:: ctypes.set_last_error error ctypes.set_last_error
 
 
@@ -2115,12 +2142,14 @@ Utility functions
 
 .. function:: WinError(code=None, descr=None)
 
-   Windows only: this function is probably the worst-named thing in ctypes. It
+   This function is probably the worst-named thing in ctypes. It
    creates an instance of :exc:`OSError`.  If *code* is not specified,
    ``GetLastError`` is called to determine the error code. If *descr* is not
    specified, :func:`FormatError` is called to get a textual description of the
    error.
 
+   .. availability:: Windows
+
    .. versionchanged:: 3.3
       An instance of :exc:`WindowsError` used to be created, which is now an
       alias of :exc:`OSError`.
@@ -2484,9 +2513,11 @@ These are the fundamental ctypes data types:
 
 .. class:: HRESULT
 
-   Windows only: Represents a :c:type:`!HRESULT` value, which contains success or
+   Represents a :c:type:`!HRESULT` value, which contains success or
    error information for a function or method call.
 
+   .. availability:: Windows
+
 
 .. class:: py_object
 
@@ -2755,7 +2786,7 @@ Exceptions
 
 .. exception:: COMError(hresult, text, details)
 
-   Windows only: This exception is raised when a COM method call failed.
+   This exception is raised when a COM method call failed.
 
    .. attribute:: hresult
 
@@ -2775,4 +2806,6 @@ Exceptions
       identifier.  *progid* is the ``ProgID`` of the interface that defined the
       error.
 
+   .. availability:: Windows
+
    .. versionadded:: next