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/ci.yml

@@ -105,7 +105,7 @@ jobs:
           buildkitd-flags: --debug
       -
         name: Build
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v4
         with:
           context: .
           platforms: linux/amd64,linux/arm64,linux/ppc64le
@@ -251,7 +251,7 @@ jobs:
           config: /tmp/buildkitd.toml
       -
         name: Build
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v4
         with:
           context: .
 
@@ -278,7 +278,7 @@ jobs:
               mirrors = ["mirror.gcr.io"]
       -
         name: Build
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v4
         with:
           context: .
 
@@ -340,7 +340,7 @@ jobs:
           EOL
       -
         name: Build
-        uses: docker/build-push-action@master
+        uses: docker/build-push-action@v4
         with:
           context: .
 
@@ -391,7 +391,7 @@ jobs:
           EOL
       -
         name: Build
-        uses: docker/build-push-action@master
+        uses: docker/build-push-action@v4
         with:
           context: .