Carry matching headers in Vulkan update proposals

[antono3]

Summary

• Select the highest numeric upstream Vulkan-Docs tag and reject downgrades.
• Generate with pinned V 0.5.2 and pair each generated registry snapshot with matching Vulkan-Headers C headers.
• Compile the target module against those bundled headers and its pinned Volk sources, then include headers in the proposed antono2/vulkan PR.

This depends on antono2/vulkan#65, which permits generated PRs to carry the matching headers and removes the hard-coded version in its setup assertion.

Verification

• Workflow YAML and embedded Bash syntax parsed.
• git diff --check passed.
• Upstream tag selection currently resolves to v1.4.364.

After both PRs merge, I will run the update workflow manually and review the generated target PR and CI.