libffi: Remove more unneeded files when merging

Delete .allow-ai-service and .gail-labels which are present in newer
versions of libffi.

libffi/ChangeLog:
	PR libffi/117635
	* merge.sh: Delete .allow-ai-service and .gail-labels when
	merging new upstream versions.

Signed-off-by: Pietro Monteiro <pietro@sociotechnical.xyz>
1 file changed