chore(deps): bump docker/build-push-action from 3 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 3 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v3...v6)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/docker.yml

@@ -66,7 +66,7 @@ jobs:
       - name: Build and export
         id: build
         if: github.ref == 'refs/heads/master'
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v6
         with:
           push: true
           platforms: linux/${{ matrix.arch }}
@@ -89,7 +89,7 @@ jobs:
       - name: Build release and export
         id: build_rel
         if: startsWith(github.ref, 'refs/tags/')
-        uses: docker/build-push-action@v3
+        uses: docker/build-push-action@v6
         with:
           push: true
           platforms: linux/${{ matrix.arch }}