BuildSystem: Automatically delete libtool files

Half of the ports had a manual post_install step to delete libtool files
this is now done automatically and there is no need for it!

Libtool files have to be deleted as libtool doesn't work while
cross-compiling (at least out of the box)

ports/gcc/build.sh

@@ -27,10 +27,3 @@ build() {
 	make -j$(nproc) all-target-libgcc CFLAGS_FOR_TARGET="$xcflags" || exit 1
 	make -j$(nproc) all-target-libstdc++-v3 || exit 1
 }
-
-post_install() {
-	# remove libtool files
-	rm -f $BANAN_SYSROOT/usr/lib/libstdc++.la
-	rm -f $BANAN_SYSROOT/usr/lib/libstdc++exp.la
-	rm -f $BANAN_SYSROOT/usr/lib/libsupc++.la
-}