github-action: bump docker/metadata-action from 4 to 5

Bumps [docker/metadata-action](https://github.com/docker/metadata-action) from 4 to 5.
- [Release notes](https://github.com/docker/metadata-action/releases)
- [Upgrade guide](https://github.com/docker/metadata-action/blob/master/UPGRADE.md)
- [Commits](docker/metadata-action@v4...v5)

---
updated-dependencies:
- dependency-name: docker/metadata-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/build-image-base.yml

@@ -59,7 +59,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for ghcr
         id: meta-ghcr
-        uses: docker/metadata-action@v4
+        uses: docker/metadata-action@v5
         with:
           images: ghcr.io/${{ github.repository }}/${{ inputs.image }}
           tags: |
@@ -74,7 +74,7 @@ jobs:
             org.opencontainers.image.title=Orange ${{ inputs.image }} (GOV.UK PaaS fork)
       - name: Extract metadata (tags, labels) for docker hub
         id: meta-dockerhub
-        uses: docker/metadata-action@v4
+        uses: docker/metadata-action@v5
         with:
           images: ${{ env.DOCKERHUB_ORG }}/${{ inputs.image }}
           tags: |