ci: upgrade docker/login-action action to v3

This update is necessary as GitHub Actions will stop supporting
Node.js 16. Version 3 now uses Node.js 20.

Reference:
https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

Signed-off-by: Renato Westphal <[email protected]>

.github/workflows/ci.yaml

@@ -79,7 +79,7 @@ jobs:
     if: github.ref == 'refs/heads/master'
     steps:
       - uses: actions/checkout@v4
-      - uses: docker/login-action@v2
+      - uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{github.actor}}