Update docker/setup-buildx-action digest to 6524bf6

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -76,7 +76,7 @@ jobs:
       - name: Setup Docker buildx
         id: buildx
         timeout-minutes: 4
-        uses: docker/setup-buildx-action@0f069ddc17b8eb78586b08a7fe335fd54649e2d3
+        uses: docker/setup-buildx-action@6524bf65af31da8d45b59e8c27de4bd072b392f5
       - name: Log into registry
         timeout-minutes: 5
         uses: docker/login-action@7ca345011ac4304463197fac0e56eab1bc7e6af0