Bump docker/metadata-action from 4.3.0 to 4.6.0 (#427)

Bumps [docker/metadata-action](https://github.com/docker/metadata-action) from 4.3.0 to 4.6.0.
- [Release notes](https://github.com/docker/metadata-action/releases)
- [Commits](507c2f2dc5...818d4b7b91)

---
updated-dependencies:
- dependency-name: docker/metadata-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/docker.yml

@@ -35,7 +35,7 @@ jobs:
       # https://github.com/docker/metadata-action
       - name: Extract Docker metadata
         id: meta
-        uses: docker/metadata-action@507c2f2dc502c992ad446e3d7a5dfbe311567a96
+        uses: docker/metadata-action@818d4b7b91585d195f67373fd9cb0332e31a7175
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           flavor: latest=${{ github.ref == 'refs/heads/master' }}