fix: add GitHub Container Registry authentication

- Add docker/login-action step to authenticate with ghcr.io
- Resolves Docker push authentication failure in release pipeline

Author: goosewin

.github/workflows/release.yml

@@ -26,6 +26,13 @@ jobs:
       - name: Run tests
         run: make test
 
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Run GoReleaser
         uses: goreleaser/goreleaser-action@v6
         with: