fix(ci): pass GH_TOKEN to release trigger guard validation step

The gh CLI was installed with GH_TOKEN but the validate step that
actually calls it was missing the env var, causing auth failure.

.github/workflows/pub-release.yml

@@ -144,6 +144,8 @@ jobs:
                     --output-json artifacts/release-trigger-guard.json \
                     --output-md artifacts/release-trigger-guard.md \
                     --fail-on-violation
+              env:
+                  GH_TOKEN: ${{ github.token }}
 
             - name: Emit release trigger audit event
               if: always()