This variable was added in commit
62c7857dfa ("package/libassuan: add host
variant"), but in fact does not make sense for a host
package. Indeed, config scripts only need to be tweaked for target
packages, and in any case, the <pkg>_CONFIG_SCRIPTS variable is only
used during staging installation (to tweak the config scripts) and
during target installation (to remove them), and neither staging nor
target installation are relevant for host packages.
Therefore, let's remove this small piece of dead code.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>