Add target platform to artifact names.

Use better gzip input name which is preserved by metadata.

Add chmod for input file and use for executables.

Signed-off-by: Jason Volk <jason@zemos.net>

.github/workflows/package.yml

@@ -96,7 +96,8 @@ jobs:
             "dst": "tuwunel.zst",
             "src": "/usr/bin/tuwunel",
             "mime": "application/zstd",
-            "zstd": 11
+            "zstd": 11,
+            "chmod": "a+x"
           }
         }