fix: use correct domain for GitHub release assets

The Python binaries are actually hosted on release-assets.githubusercontent.com,
not *.actions.githubusercontent.com

Author: taeold

.github/workflows/conformance.yml

@@ -34,7 +34,7 @@ jobs:
           proxy.golang.org:443
           pypi.org:443
           storage.googleapis.com:443
-          *.actions.githubusercontent.com:443
+          release-assets.githubusercontent.com:443
 
     - name: Checkout code
       uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2