Update docker/metadata-action action to v5.9.0 (#48)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/release.yml

@@ -42,7 +42,7 @@ jobs:
 
       - name: Extract metadata
         id: meta
-        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
+        uses: docker/metadata-action@318604b99e75e41977312d83839a89be02ca4893 # v5.9.0
         with:
           images: ghcr.io/${{ steps.repo_owner.outputs.OWNER }}/plotting-mcp
           tags: |