[Chore] Bump Python version and apply formatting changes for v0.12 release

[DarkLight1337]

PLEASE FILL IN THE PR DESCRIPTION HERE ENSURING ALL CHECKLIST ITEMS (AT THE BOTTOM) HAVE BEEN CONSIDERED.

Purpose

• Update minimum Python version to 3.10, in line with upstream
• Replace black and isort with ruff
• Apply formatting changes by ruff for the new Python version
• Update dev packages to match vLLM upstream

FIX #54

Test Plan

Test Result

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Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.
• (Optional) Release notes update. If your change is user facing, please update the release notes draft.

BEFORE SUBMITTING, PLEASE READ https://github.com/vllm-project/vllm-omni/blob/main/CONTRIBUTING.md (anything written below this line will be removed by GitHub Actions)

[ywang96]

@DarkLight1337 vllm-omni is currently based on 0.11.0 - is this change really necessary?

[DarkLight1337]

Oh, sorry I misread the comment in #33. We can merge this PR after the branch cut then.

[ZJY0516]

This is needed by doc build as i recall. cc @Gaohan123

[DarkLight1337]

Let me mark this as draft for now until it is confirmed that we can safely apply these changes without affecting the initial release