Fix Gemma test to unbreak head

[IvyZX]

• Loosen the JAX broadcast check
• Modify some typing annotations to be runnable on Python 3.9

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 0.00%. Comparing base (31adb00) to head (1c4e348). Report is 24 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #4025 +/- ## ====================================== Coverage 0.00% 0.00% ====================================== Files 106 107 +1 Lines 13582 13689 +107 ====================================== - Misses 13582 13689 +107 ```

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