PIMOB-2627: Fix UI Tests in GHA

[jheng-hao-lin-cko]

Issue

PIMOB-2627

Proposed changes

Specify Mac OS image in GHA

Test Steps

Run UI test workflow and it should pass

Checklist

• [x] Reviewers assigned
• [x] I have performed a self-review of my code and manual testing
• [x] Lint and unit tests pass locally with my changes