chore: onboard stepsecurity and apply security best practice

[ali-kafel]

This pull request updates the GitHub Actions workflows for linting and testing to improve security and reliability. The main changes include hardening the runners, pinning all third-party actions to specific commit hashes for better supply chain security, and updating the permissions for jobs.

Security hardening and reliability improvements:

• Added the step-security/harden-runner action to all jobs in .github/workflows/lint.yml and .github/workflows/test.yml to restrict network egress and apply a global-allowed-endpoints policy. [1] [2]
• Set permissions: id-token: write for all jobs to enable secure OIDC-based authentication for actions that require it. [1] [2]

Dependency pinning for supply chain security:

• Updated all third-party GitHub Actions in both workflow files to use specific commit SHAs instead of floating tags, ensuring reproducible and secure builds. [1] [2] [3]

Documentation and consistency:

• Updated commented-out steps in .github/workflows/lint.yml to also use pinned action SHAs for consistency, even though these steps are currently disabled.