Fix typo in config script to re-enable libtorch build and test in macOS CI (#32072)
Summary:
Currently, libtorch build and test are not running in macOS CI. This PR fixes the issue.
**Test Plan:**
Check that libtorch build and test are running again in macOS CI.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32072
Differential Revision: D19373615
Pulled By: yf225
fbshipit-source-id: 28686ef5895358a2b60db46b1946f21c58c6a18e
