Bump scality/metadata in /.github/docker

Bumps scality/metadata from 8.11.0-standalone to 8.25.0-standalone.

---
updated-dependencies:
- dependency-name: scality/metadata
  dependency-version: 8.25.0-standalone
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/docker/docker-compose.yaml

@@ -129,7 +129,7 @@ services:
     depends_on:
       - redis
   metadata-standalone:
-    image: ghcr.io/scality/metadata:8.11.0-standalone
+    image: ghcr.io/scality/metadata:8.25.0-standalone
     profiles: ['metadata-standalone']
     network_mode: 'host'
     volumes: