Use Workflow URIs for source.yaml (#1189)

Signed-off-by: egibs <20933572+egibs@users.noreply.github.com>

Author: egibs

.chainguard/source.yaml

@@ -8,9 +8,9 @@ spec:
           - issuer: https://accounts.google.com
           - issuer: https://github.com/login/oauth
           - issuer: https://token.actions.githubusercontent.com
-            subject: chainguard-dev/malcontent/.github/workflows/release.yaml@refs/heads/main
+            subject: https://github.com/chainguard-dev/malcontent/.github/workflows/release.yaml@refs/heads/main
           - issuer: https://token.actions.githubusercontent.com
-            subject: chainguard-dev/malcontent/.github/workflows/third-party.yaml@refs/heads/main
+            subject: https://github.com/chainguard-dev/malcontent/.github/workflows/third-party.yaml@refs/heads/main
     - key:
         # allow commits signed by GitHub, e.g. the UI
         kms: https://github.com/web-flow.gpg