Updated github action versions

[agsaru]

Summary

Updated github runner to use ubuntu-22.04 instead of ubuntu-latest for stabilty and code consistency.
Used latest github action stable version commits inplace of older versions of actions.

Tests

• Unit tests added/updated
• Reproduction script provided (required for Core Runtime)
• CI passes
• If tests are impractical: explain why below and provide manual evidence above

Non-Goals

AI Tool Usage

• No AI tools were used in this contribution
• AI tools were used (describe below)

[Copilot]

Pull request overview

Updates GitHub Actions workflow dependencies to improve CI stability and consistency by pinning the runner OS and action versions.

Changes:

• Switch workflow jobs from ubuntu-latest to ubuntu-22.04.
• Pin commonly used GitHub Actions (checkout/setup-python/cache/artifacts/download-artifact/test-reporter/codecov) to specific commit SHAs.

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[greptile-apps]

Greptile Summary

This PR pins all GitHub Action references to full commit SHAs (replacing floating tags like @v4) and switches all three jobs from ubuntu-latest to ubuntu-22.04. Several actions receive major version bumps (e.g. actions/checkout v4→v6, actions/upload-artifact v4→v7, actions/download-artifact v4→v8, dorny/test-reporter v1→v3), which the author has verified via CI.

Confidence Score: 5/5

Safe to merge — a routine CI maintenance update with CI confirmed passing.

All changes are mechanical action-version and runner updates. Previous reviewer concerns were addressed. No logic changes, no security issues, and CI passes per the PR checklist.

No files require special attention.

Important Files Changed

Filename	Overview
.github/actions/run-ux-tests/action.yml	Pins all action references to full commit SHAs with version comments; major bumps include checkout v4→v6, upload-artifact v4→v7, codecov v5→v6, and setup-miniconda to a pinned SHA.
.github/workflows/ux-tests.yml	Replaces ubuntu-latest with ubuntu-22.04 across all three jobs and pins all action SHAs; notably upload-artifact is pinned to v7.0.1 while download-artifact is pinned to v8.0.1 in the same workflow.

_{Reviews (4): Last reviewed commit: "Merge branch 'master' into action-update" | Re-trigger Greptile}