Bump docker/metadata-action

Bumps [docker/metadata-action](https://github.com/docker/metadata-action) from b798ed8388581f6f002541048b6458ca2c4ba442 to c1e51972afc2121e065aed6d45c65596fe445f3f.
- [Release notes](https://github.com/docker/metadata-action/releases)
- [Commits](docker/metadata-action@b798ed8...c1e5197)

---
updated-dependencies:
- dependency-name: docker/metadata-action
  dependency-version: c1e51972afc2121e065aed6d45c65596fe445f3f
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/release.yml

@@ -51,7 +51,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@b798ed8388581f6f002541048b6458ca2c4ba442
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f
         with:
           images: helvethink/gitlab-ci-exporter