fix(hal/vulkan): Use queue family index modified by device open callback

[andyleiserson]

Just a small thing I noticed. family_info was not routed through the callback, so if the callback did modify queue_create_infos, an incorrect index could be used.

Also updates the doc comment for CreateDeviceCallbackArgs::queue_create_infos.

Testing
Untested

Squash or Rebase? Squash

Checklist

• I self-reviewed and fully understand this PR.
• WebGPU implementations built with wgpu may be affected behaviorally.
• Validation and feature gates are in place to confine behavioral changes.
• Tests demonstrate the validation and altered logic works.
• CHANGELOG.md entries for the user-facing effects of this change are present.
• The PR is minimal, and doesn't make sense to land as multiple PRs.
• Commits are logically scoped and individually reviewable.
• The PR description has enough context to understand the motivation and solution implemented.

[ErichDonGubler]

LGTM. I have some questions and suggestions, but nothing that seems significant enough to block.