fix: address code review — publish.yml permissions, test docstrings

- Add contents: read permission to publish.yml (required for actions/checkout)
  when any permission is explicitly set, unlisted permissions default to none
- Add timeout-minutes: 15 to publish.yml for consistency with ci.yml
- Add docstrings to 3 pyproject metadata test functions for consistency
  with the rest of the 2000+ line test file

.github/workflows/publish.yml

@@ -6,11 +6,13 @@ on:
       - "v*"
 
 permissions:
+  contents: read   # Required for actions/checkout
   id-token: write  # Required for OIDC Trusted Publisher
 
 jobs:
   publish:
     runs-on: ubuntu-latest
+    timeout-minutes: 15
     environment: pypi
     steps:
       - uses: actions/checkout@v4