refactor: improve Gitea registry login step by adding username variable and logging

.gitea/workflows/docker-build-push.yml

@@ -121,8 +121,12 @@ jobs:
       - name: Log in to Gitea Registry
         env:
           REGISTRY: ${{ steps.vars.outputs.registry }}
+          REGISTRY_USERNAME: ${{ secrets.REGISTRY_USERNAME }}
         run: |
-          echo "${{ secrets.GITEA_TOKEN }}" | docker login "$REGISTRY" -u "$GITHUB_ACTOR" --password-stdin
+          set -eu
+          USER_NAME="${REGISTRY_USERNAME:-$GITHUB_ACTOR}"
+          echo "Logging into $REGISTRY as $USER_NAME"
+          echo "${{ secrets.GITEA_TOKEN }}" | docker login "$REGISTRY" -u "$USER_NAME" --password-stdin
 
       - name: Ensure buildx builder
         run: |