Update docker/metadata-action digest to 906ecf0

Author: renovate[bot]

.github/workflows/ghcr-io-docker-build.yaml

@@ -52,7 +52,7 @@ jobs:
       # https://github.com/docker/metadata-action
       - name: Extract Jenkins Docker metadata
         id: meta
-        uses: docker/metadata-action@b53be03109c4ef6f6cc7aa545b84b17a7fe51c1e
+        uses: docker/metadata-action@906ecf0fc0a80f9110f79d9e6c04b1080f4a2621
         with:
           images: ${{ env.REGISTRY }}/${{ github.actor }}/jenkinsdsl