Only setup local cache when arn is missing

Author: brianmichel

.github/actions/setup-sccache/action.yml

@@ -67,6 +67,7 @@ runs:
         variant: sccache
 
     - name: Setup sccache (local)
+      if: inputs.aws-arn == ''
       uses: hendrikmuhs/ccache-action@a1209f81afb8c005c13b4296c32e363431bffea5 # v1.2.17
       with:
         max-size: ${{ inputs.disk-max-size }}