[gn-hiro-v]

This updates every standard Ubuntu workflow runner in this repository to Depot's Ubuntu runner while preserving the Linux x64 environment.

Related issue(s)

None.

Checklist

• I have read the contributing guidelines.
• I have referenced a design issue if this introduces a feature.
• I am following the contributing code guidelines.
• I have read the security policy.
• This pull request does not address a security vulnerability.
• I have added tests that prove my fix is effective or that my feature works.
• I have added or changed the documentation.

Further Comments

Validation: git diff --check passes. actionlint reports existing warnings about old action versions in unrelated workflows; Depot runner labels were recognized with a temporary actionlint runner-label config. This runner-label migration does not change application behavior.