[WIP] Fix release CI

[Copilot]

• Analyze repository structure and understand the issues
• Identify the regex pattern issue in tool/bump_version.py
• Identify the git rebase issue in .github/workflows/release.yml
• Fix the regex pattern in _replace_version function to use proper group reference
• Fix the CI workflow to handle git state properly before rebase
• Test the fixes to ensure they work correctly
• Validate the changes don't break existing functionality

Issues Found:

1. Regex Issue: The rf"\g<1>{new_version}" pattern in _replace_version function causes "invalid group reference 10" when new_version contains digits that get concatenated with the group reference (e.g., \g<1>1.0.10 becomes \g<110>).

2. Git Rebase Issue: The release CI workflow tries to rebase after making commits, but the script modifies files without properly managing git state, causing "You have unstaged changes" error.

Plan:

• Fix the regex pattern by separating the group reference from the variable substitution
• Update the CI workflow to properly handle git state management around the rebase operation

Fixes #9.

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