Update to 4.28
    
    - New upstream release 4.28
      - Validate the JSON struct, which might get corrupted by wrong FREEZE/THAW
        methods, or other serializers, or corrupting our magic object (GH#192)
      - Improve our DESTROY and END methods to avoid NULL dereferences
        (https://github.com/rurban/perl-compiler/issues/438)
      - Fix 3 tests in t/20_unknown.t with the latest 5.35.10 bool enhancements and
        JSON::PP (GH#194)
      - Fix t/118_type.t with Windows ivtype long long (GH#178)
      - Added GitHub actions