Fix release

Release has been failing for a while (e.g.
https://github.com/google/copybara/actions/runs/14706485491)

The issue is that the token used for creating tags/releases need
the content write permission.

Change-Id: I43382eb95105326c90975673087c7a6a324c1271

Author: mikelalcon

.github/workflows/release.yaml

@@ -1,5 +1,8 @@
 name: Weekly Release
 
+permissions:
+      contents: write
+
 on:
   #  Uncoment these two lines to test the pipeline in a PR, but NEVER merge in main branch:
   #  pull_request: