Replace checks of "CI" environment variable with conftest fixture in model tests

[skhorasganiTT]

All checks of os.getenv("CI") should be replaced with the is_ci_env fixture where possible, as per the request of @tt-rkim.

• [x] #10403
• [ ] #10404
• [x] #10405

[mtairum]

@skhorasganiTT How important is this requirement?

We rely on Mixtral env flags to locate the weights and cache files. This needs to be exported before we load the model library, which pins the location during init.

Using fixtures for this scenario means either moving the library loading to inside the test call or passing these path flags when loading the model config.

[tt-rkim]

I would encourage model team to replace everything with this. We need to centralize our environment variable usage and also reduce our workload in the future when we move caching file systems away from MLPerf.

If you mean TtModelArgs folder values, could you perhaps initialize these when TtModelArgs is constructed in mistral7b?

[mtairum]

Done for Mistral and Mixtral.

[tt-rkim]

Thank you!!!

@kevinmiTT11 @cglagovichTT any update on llama?

[cglagovichTT]

This is on the backlog - we should be able to get to it within a week