deps/gha: 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](https://github.com/docker/metadata-action/compare/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/container-build.yml

@@ -84,7 +84,7 @@ jobs:
       # Compute metadata
       - name: Extract metadata
         id: meta
-        uses: docker/metadata-action@v4
+        uses: docker/metadata-action@v5
         with:
           images: bunkerity/${{ inputs.IMAGE }}
       # Build cached image

.github/workflows/linux-build.yml

@@ -135,7 +135,7 @@ jobs:
       - name: Extract metadata
         if: inputs.TEST == true
         id: meta
-        uses: docker/metadata-action@v4
+        uses: docker/metadata-action@v5
         with:
           images: ghcr.io/bunkerity/${{ inputs.LINUX }}-tests:${{ inputs.RELEASE }}
       - name: Build test image

.github/workflows/push-docker.yml

@@ -63,7 +63,7 @@ jobs:
       # Compute metadata
       - name: Extract metadata
         id: meta
-        uses: docker/metadata-action@v4
+        uses: docker/metadata-action@v5
         with:
           images: bunkerity/${{ inputs.IMAGE }}
       # Build and push