chore(deps): update docker/setup-buildx-action action to v4.1.0

Author: renovate[bot]

.github/workflows/build-testflinger-testenv-container.yml

@@ -31,7 +31,7 @@ jobs:
 
     steps:
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
+        uses: docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5 # v4.1.0
         with:
           cache-binary: false
           buildkitd-config-inline: |

.github/workflows/server-charm-release.yml

@@ -40,7 +40,7 @@ jobs:
 
     steps:
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
+        uses: docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5 # v4.1.0
         with:
           cache-binary: false
           buildkitd-config-inline: |