chore(deps): update docker/build-push-action action to v6

Author: renovate[bot]

.github/workflows/ci-pr.yml

@@ -70,7 +70,7 @@ jobs:
             type=raw,value=latest
 
       - name: Build
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: linux/amd64,linux/arm64

.github/workflows/ci-release.yml

@@ -67,7 +67,7 @@ jobs:
             type=semver,pattern={{raw}}
 
       - name: Build
-        uses: docker/build-push-action@v4
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: linux/amd64,linux/arm64