fix: fallback to reading cpus.yaml relative to current dir

[sthaha]

This commit fixes the issue of having to copy cpus.yaml to /var/lib/kepler (the hardcoded path for the cpus.yaml) by reading the cpus.yaml file relative to the project root.

Thus the following now works fine.

make build
sudo ./_output/bin/kepler

[github-actions]

🤖 SeineSailor

Here is a concise summary of the pull request changes:

Summary: This pull request introduces a fix to allow reading the cpus.yaml file relative to the project root, eliminating the need for a hardcoded path. Key modifications include:

• Introduction of a new readCPUModelData() function to read the file from CPUModelDataPath or ./data/cpus.yaml as a fallback.
• Updated getCPUMicroArchitecture function signature to accept family, model, and stepping strings as arguments.
• Replacement of os.ReadFile(CPUModelDataPath) with readCPUModelData().

Impact: These changes do not affect the external interface or behavior of the code, but improve flexibility and maintainability by allowing the cpus.yaml file to be read from a relative path.

Observations: The changes are well-contained and do not introduce any breaking changes. However, it would be beneficial to consider adding tests to ensure the new readCPUModelData() function behaves as expected in different scenarios.

[gdozortsev]

Tried this locally and it works now