build(deps): bump docker/build-push-action from 2 to 3 (#573)

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 2 to 3.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v2...v3)

---
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/on-main-push.yaml

@@ -48,7 +48,7 @@ jobs:
         id: tags
 
       - name: Build image
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           context: .
           file: cmd/kured/Dockerfile.multi

.github/workflows/on-tag.yaml

@@ -52,7 +52,7 @@ jobs:
         uses: docker/setup-buildx-action@v1
 
       - name: Build image
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           context: .
           file: cmd/kured/Dockerfile.multi