bump version to v0.12.1

[lvhan028]

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Motivation

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Modification

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BC-breaking (Optional)

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Checklist

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3. If the modification has a dependency on downstream projects of a newer version, this PR should be tested with all supported versions of downstream projects.
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[Copilot]

Pull request overview

Bumps LMDeploy’s release version to v0.12.1 and updates user-facing installation instructions to reference the new release tag and wheel URLs.

Changes:

• Update lmdeploy package version constant to 0.12.1.
• Refresh installation docs (EN/ZH) and READMEs to use LMDEPLOY_VERSION=0.12.1 in download examples.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
lmdeploy/version.py	Bumps the library’s __version__ to 0.12.1.
docs/zh_cn/get_started/installation.md	Updates the pinned release version in CUDA 11+ wheel install example.
docs/en/get_started/installation.md	Updates the pinned release version in CUDA 11+ wheel install example.
README_zh-CN.md	Updates the pinned release version in the CUDA 12.8 wheel install example.
README.md	Updates the pinned release version in the CUDA 12.8 wheel install example.

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