chore(deps): update ghcr.io/astral-sh/uv docker tag to v0.9.21

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
ghcr.io/astral-sh/uv	final	patch	0.9.18 → 0.9.21

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Release Notes

astral-sh/uv (ghcr.io/astral-sh/uv)

v0.9.21

Compare Source

Released on 2025-12-30.

Bug fixes

• Fix regression where zstd distribution hashes were not considered valid (#​17265)

Documentation

• Fix a typo in the resolution documentation (#​17258)
• Fix a typo in python install --default documentation (#​9826)

v0.9.20

Released on 2025-12-29.

This is a re-release of 0.9.20, with internal crate versions incremented to enable publishing to crates.io.

v0.9.19

Released on 2025-12-29.

Python

• Add CPython 3.15.0a3 (#​17165)

Enhancements

• Allow uv pip compile to install missing python interpreters in cases where it would otherwise fail (#​17216)
• Avoid creating file contents with uv init --bare --script (#​17162)
• Respect --torch-backend in uv tool commands (#​17117)
• Support comma-separated values in --no-binary and --only-binary (#​17185)

Preview features

• Summarize package changes in uv sync with JSON output format (#​16981)

Performance

• Avoid two hot String allocations in deserialization (#​17221)
• Cache NVIDIA-hosted wheels by default (#​17164)

Bug fixes

• Avoid enforcing incorrect hash in mixed-hash settings (#​17157)
• Fix retry counts in cached client (#​17104)
• Respect UV_PYTHON_DOWNLOAD_MIRROR in uv python list (#​16673)
• Support remote pylock.toml files (#​17119)
• Avoid flagging proxied Git URLs as ambiguous authority (#​17234)
• Fix dropped support of - in pip constraints, overrides, and excludes (#​17188)

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