Update docker/metadata-action digest to 906ecf0

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -87,7 +87,7 @@ jobs:
       - name: Extract Docker metadata
         id: meta
         timeout-minutes: 5
-        uses: docker/metadata-action@38b36773831fce8789962056bf155ba063580c34
+        uses: docker/metadata-action@906ecf0fc0a80f9110f79d9e6c04b1080f4a2621
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           tags: |