tests: update fixtures for algorithm and evaluation tests

[johannaSommer]

Description

In this PR, we update the test setup in several ways:

• tiny fixtures: where not already the case, we replace fixture references to "large models" like opt125m with their tiny variants
• outdated fixtures: where possible, we make flux the default fixture for testing
• unused fixtures: since switching to the tiny models for testing, we have a few unused fixtures that I have removed

Related Issue

None.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Ran tests via the nightlies.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Additional Notes

None.

[johnrachwan123]

LGTM

[cursor]

Bug: Compiler Alters Global Logging, Suppresses Important Messages

The StableFastCompiler permanently sets the global root logger level to WARNING. This modifies the application's global logging state, suppressing important log messages from other parts of the system throughout its lifetime, rather than temporarily for the compilation operation.