Remove pyre-fixme/pyre-ignore from ax/utils/ source files

[saitcakmak]

Summary:
Remove ~125 pyre-fixme/pyre-ignore suppression comments from 21 source files
in ax/utils/ by applying proper type fixes:

• Use none_throws() for Optional unwrapping (e.g., grad access, sim_start_time)
• Use cast() for GPyTorch model and FixedFeatureModel narrowing
• Fix covariant TypeVar issue in Result.unwrap_or with new TypeVar U
• Add proper annotations to StreamHandler[Any], Callable[..., Any]
• Use helper functions for dynamic GPyTorch attribute access
• Use np.asarray() for numpy return type consistency
• Fix scipy stub limitations with positional args
• Use record.__dict__ for safe attribute assignment

All 100 tests pass (0 failures across 6 test targets).

Differential Revision: D95265024

[meta-codesync]

@saitcakmak has exported this pull request. If you are a Meta employee, you can view the originating Diff in D95265024.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 81.71429% with 32 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.83%. Comparing base (f973cb4) to head (2d6bc40).

Files with missing lines	Patch %	Lines
ax/utils/stats/no_effects.py	7.40%	25 Missing ⚠️
ax/utils/sensitivity/derivative_gp.py	84.37%	5 Missing ⚠️
ax/utils/common/executils.py	66.66%	1 Missing ⚠️
ax/utils/sensitivity/sobol_measures.py	98.21%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4983   +/-   ##
=======================================
  Coverage   96.83%   96.83%           
=======================================
  Files         599      599           
  Lines       64518    64583   +65     
=======================================
+ Hits        62473    62536   +63     
- Misses       2045     2047    +2     

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[meta-codesync]

This pull request has been merged in 9f50a93.