test: mark functions not modifying state as pure

[thelostone-mc]

Description

Functions in test which do not modify state can be set to pure

How Has This Been Tested?

forge test

Checklist:

Before deployment

• 100% test and branch coverage
• check slither for severe issues
• fuzz and invariant tests (when applicable)
• formal verification (when applicable)
• deployment or upgrade scripts ready

After deployment

• transfer ownership after deployments (when applicable)
• complete upgrade (when applicable)
• generate deployment/upgrade log files

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Considerations

• I have followed the contributing guidelines.
• My code follows the style guidelines of this project and I have run forge fmt and prettier to ensure the code style is valid
• 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
• My changes generate no new warnings
• 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 context

Add any other context about the pull request here.

[zhongeric]

Ah, can you sign your commits please?