fix(ci): add required permissions to changesets workflow

- Add 'contents: write' for committing version changes
- Add 'pull-requests: write' for creating Release PRs

These permissions are required for changesets/action to properly
create and manage the Release PR workflow.

Author: phoenix-server

.github/workflows/changesets.yml

@@ -12,6 +12,9 @@ jobs:
     name: Release
     runs-on: ubuntu-latest
     environment: release
+    permissions:
+      contents: write
+      pull-requests: write
     steps:
       - name: Checkout
         uses: actions/checkout@v3