ci: pins all reference GitHub actions to a hash value

[jpower432]

Description

Pinning GitHub Actions to a commit-sha is a safer practice and supported by Dependabot for continuous updates

Type of change

• New feature (non-breaking change which adds functionality) Maintenance Only

How has this been tested?

• Verify changes locally with act
• Verify changes in fork with GitHub Actions
  • Demonstrated ci.yml with this PR
  • Publish - https://github.com/jpower432/trestle-bot/actions/runs/9422275168/job/25958179482

Test Configuration:

• Firmware version:
• Hardware:
• Toolchain:
• SDK:

Checklist

• My code follows the style guidelines of this project
• 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
• Any dependent changes have been merged and published in downstream modules

[gvauter]

LGTM