[CI] Validate GPU frequency before GPU jobs

[RMLYC]

Closes #216

Summary

• add a GPU pre-check step in CI GPU jobs to read current graphics clock
• validate all detected GPUs are running at 1830 MHz with retries and clear per-GPU logs
• fail early when GPU frequency is not 1830 MHz to avoid unreliable test runs

Test plan

• PRE_COMMIT_HOME=/tmp/pre-commit-cache pre-commit run --all-files
• GPU frequency check execution on self-hosted runner (to be validated in CI)

[gemini-code-assist]

Note

Gemini is unable to generate a summary for this pull request due to the file types involved not being currently supported.

[xZacky]

Checking GPU frequency before testing is not feasible, because after frequency locking, if there is no workload on the GPU, the frequency will still remain very low.