fix docker push permissions

Author: syphar

.github/workflows/main.yml

@@ -7,10 +7,14 @@ on:
       - master
   pull_request: {}
 
-concurrency: 
+concurrency:
   group: ${{ format('{0}/{1}', github.repository_owner, github.ref) }}
   cancel-in-progress: true
 
+permissions:
+  contents: read
+  packages: write
+
 jobs:
   lint:
     name: Lint
@@ -45,7 +49,7 @@ jobs:
         uses: docker/login-action@v3
         with:
           registry: ghcr.io
-          username: ${{ github.repository_owner }}
+          username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
         if: github.event_name == 'push' && github.ref == 'refs/heads/master'