Resolve aspect test build issue on mac

[andponlin-canva]

Checklist

• [x] I have filed an issue about this change and discussed potential changes with the maintainers.
• [ ] I have received the approval from the maintainers to make this change.
• [x] This is not a stylistic, refactoring, or cleanup change.

Please note that the maintainers will not be reviewing this change until all checkboxes are ticked. See the Contributions section in the README for more details.

Discussion thread for this change

Issue number: 6917

Description of this change

This resolves a problem in the test where the pattern for matching bazel-out does not accommodate the Mac's directory paths.