ci: scope down permissions for finch-vm-test.yaml

Signed-off-by: Adnan Khan <adnanek@amazon.com>

Author: AdnaneKhan

.github/workflows/finch-vm-test.yaml

@@ -13,6 +13,9 @@ on:
   workflow_dispatch:
 env:
   GO_VERSION: '1.24.x'
+permissions:
+  contents: read
+
 jobs:
   mac-test-e2e:
     runs-on: codebuild-finch-daemon-arm64-2-instance-${{ github.run_id }}-${{ github.run_attempt }}