fix(ci): regenerate pixi.lock to resolve CI setup failures

This infrastructure fix addresses the universal pixi setup failures in CI
(4-11 second failures) by regenerating the out-of-sync pixi.lock file.

- Removed outdated pixi.lock file
- Regenerated with `pixi install` to sync dependencies
- Resolves pixi environment installation failures across all CI environments
- Unblocks CI validation for comprehensive CI fixes in PR #8

This fix specifically targets the pixi setup infrastructure issue that was
preventing validation of the comprehensive CI improvements.

Co-Authored-By: MementoRC (https://github.com/MementoRC)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: MementoRC