chore(deps): update docker/build-push-action action to v6.15.0

Author: renovate[bot]

.github/actions/build-image/action.yaml

@@ -57,7 +57,7 @@ runs:
         username: ${{ github.actor }}
         password: ${{ github.token }}
     - name: Build and push Docker image
-      uses: docker/build-push-action@ca877d9245402d1537745e0e356eab47c3520991 # v6.13.0
+      uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6.15.0
       id: build-image
       with:
         context: .