chore: bump docker/build-push-action from 3 to 4 (coder#5946)

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](docker/build-push-action@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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/dogfood.yaml

@@ -40,7 +40,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_PASSWORD }}
 
       - name: Build and push
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v4
         with:
           context: "{{defaultContext}}:dogfood"
           push: true