ci: retire unavailable Vulkan GPU gate

[Irk2wd]

Summary

• remove the GitHub Actions Vulkan GPU gate that cannot run without a persistent self-hosted runner
• keep the 21-mode Vulkan harness and strict GPU/validation qualification available for explicit local use
• document that local qualification is not an automated PR gate

Validation

• python -B tools/threading/test_run_parallel_record_vulkan_test.py (164/164)
• git diff --check
• independent P0-P2 review: clean

Repository configuration

• verified before rollout: main has required_status_checks = null
• verified before rollout: repository ruleset count = 0
• Vulkan GPU Gate was never a required context

Follow-up after merge

• delete the now-unused vulkan-gpu-persistent repository Environment

[Irk2wd]

@codex review

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 0077c6cbe1

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[Irk2wd]

@codex review

Please re-review exact head 0077c6cbe17cf94d951ba8d8fbd89715190c3f65 after the P1 discussion was resolved with live repository evidence: main has required_status_checks = null and the repository has zero rulesets, so no required Vulkan GPU Gate context exists to remove. Report any remaining actionable P0-P2 issues.

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. More of your lovely PRs please.

Reviewed commit: 0077c6cbe1

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".