fix: quote JOB_INDEX in cp command for shellcheck SC2086

Made-with: Cursor

Author: adamtheturtle

.github/workflows/test.yml

@@ -140,7 +140,7 @@ jobs:
           # See the "CI Setup" document for details of how this was set up.
           ci/decrypt_secret.sh
           tar xvf "${HOME}"/secrets/secrets.tar
-          cp ./ci_secrets/vuforia_secrets_${JOB_INDEX}.env ./vuforia_secrets.env
+          cp "./ci_secrets/vuforia_secrets_${JOB_INDEX}.env" ./vuforia_secrets.env
 
       # We have seen issues with running out of disk space on test_docker
       - name: Free Disk Space (Ubuntu)