ci: temporarily clean cache to fix docker builds

.github/workflows/ci.yml

@@ -39,6 +39,10 @@ jobs:
         uses: docker/setup-qemu-action@v2
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v2
+      # temporarily clear out cache
+      - name: Remove cache
+        run: |
+          rm -rf /tmp/.buildx-cache
       - name: Cache Docker layers
         uses: actions/cache@v3
         with: