uv 0.12.3: CPython 3.13.15 support, performance, and preview features

The uv 0.12.3 release adds support for CPython 3.13.15 and includes several performance improvements, such as reduced Linux startup latency and faster conflict resolution. Preview features offer more control over cache size output and improved memory usage for large workspaces. This patch update is relevant for all users of uv, particularly those working with newer Python versions or large projects.

• →Add PEP 740 attestations to the GitHub Actions publishing example
• →Restrict the GitHub Actions publishing example to Python version tags
• →Correct --python-pin to --pin-python in the uv init --bare example