CI: Use uv for faster dependency installation

[amureki]

Summary by CodeRabbit

• Chores
  • Updated CI/CD pipeline configuration to optimize testing infrastructure and build processes.

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[coderabbitai]

📝 Walkthrough

Walkthrough

The CI workflow is refactored to use astral-sh/setup-uv@v7 instead of setup-python, removes dependency caching and explicit pip installation, and invokes tox via uvx. Changes apply consistently to both SQLite and PostgreSQL test jobs.

Changes

Cohort / File(s)	Summary
CI Tooling Update .github/workflows/ci.yml	Replaces setup-python with astral-sh/setup-uv@v7 for Python setup. Removes Python dependency cache configuration and explicit pip install step. Invokes tox via uvx tox run -e instead of direct tox run -e. Changes applied to both sqlite-tests and postgresql-tests job stages.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 With uv so swift and new,
Our workflows skip the old, tired queue,
No caching, no pip in sight,
Just uvx making CI light! ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title accurately describes the main change: replacing setup-python with uv for faster dependency installation in CI workflows.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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