tinyllama w/ mps error when running on ios benchmark app

[guangy10]

🐛 Describe the bug

There are three tests running in the app:

• test_load* (failed)
• test_forward* (passed)
• test_generate* (passed)

It's weird that the load_test* failed but forward and generate passed.

Job links:

• https://github.com/pytorch/executorch/actions/runs/12399052782/job/34614070197
• https://github.com/pytorch/executorch/actions/runs/12384585879/job/34573232998

I checked the log, and it seems like the issue is iOS 17 specific. As you can see the same test passed on iOS 18 here: https://github.com/pytorch/executorch/actions/runs/12399052782/job/34614070197#step:14:2618, but failed on iOS 17 on all types of iPhone 15

Versions

nightly

[guangy10]

cc: @shoumikhin @huydhn