chore(cloudxr): bump runtime SDK version to 6.2.1

[yanziz-nvidia]

Summary

Bumps the CloudXR runtime SDK version from 6.2.0 to 6.2.1 in deps/cloudxr/.env.default (CXR_RUNTIME_SDK_VERSION).

The web SDK version (CXR_WEB_SDK_VERSION) is left unchanged at 6.2.0.

This enabled SFE for supported GPUs on Linux.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Chores
  • Updated the CloudXR runtime SDK to version 6.2.1.

[coderabbitai]

📝 Walkthrough

Walkthrough

The default CloudXR runtime SDK version in deps/cloudxr/.env.default was updated from 6.2.0 to 6.2.1.

Estimated code review effort: 1 (Trivial) | ~2 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: bumping the CloudXR runtime SDK version to 6.2.1.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch yanziz/bump-cloudxr-runtime-6.2.1

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