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/expat/build.sh

@@ -4,8 +4,3 @@ NAME='expat'
 VERSION='2.7.1'
 DOWNLOAD_URL="https://github.com/libexpat/libexpat/releases/download/R_2_7_1/expat-$VERSION.tar.gz#0cce2e6e69b327fc607b8ff264f4b66bdf71ead55a87ffd5f3143f535f15cfa2"
 CONFIG_SUB=('conftools/config.sub')
-
-post_install() {
-	# remove libtool file
-	rm -f $BANAN_SYSROOT/usr/lib/libexpat.la
-}