Port everything away from PKGMETA

keep an empty PKGMETA.yml for now until all users are adjusted and
deployed.

perl-Algorithm-Diff/PKGBUILD

@@ -13,6 +13,9 @@ depends=('perl')
 license=('GPL' 'PerlArtistic')
 source=("https://cpan.metacpan.org/authors/id/R/RJ/RJBS/${_realname}-${pkgver}.tar.gz")
 sha256sums=('0022da5982645d9ef0207f3eb9ef63e70e9713ed2340ed7b3850779b0d842a7d')
+msys2_references=(
+  'cygwin'
+)
 
 build() {
   cd ${_realname}-${pkgver}