ci: add workflow permissions to pgtest

Author: NGPixel

.github/workflows/dev-db-pgtest.yml

@@ -51,6 +51,9 @@ jobs:
     name: Build PostgreSQL Docker Images
     runs-on: ubuntu-latest
     needs: [migrate]
+    permissions:
+      contents: read
+      packages: write
 
     steps:
     - uses: actions/checkout@v3