Bump docker/build-push-action from 3 to 4

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 3 to 4.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v3...v4)

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

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

.github/workflows/artifacts.yml

@@ -181,7 +181,7 @@ jobs:
         with:
           images: ghcr.io/${{ github.repository }}
           tags: nightly
-      - uses: docker/build-push-action@v3
+      - uses: docker/build-push-action@v4
         with:
           context: .
           file: server/Dockerfile

.github/workflows/release.yml

@@ -27,7 +27,7 @@ jobs:
           registry: ghcr.io
           username: ${{github.actor}}
           password: ${{secrets.GITHUB_TOKEN}}
-      - uses: docker/build-push-action@v3
+      - uses: docker/build-push-action@v4
         with:
           context: .
           file: server/Dockerfile