feat(manager/pixi): full support

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Changes

Full support of pixi, both pypi packages and conda packages.

based on #34351 and #34400 and #34681

Ther are merged in to this branch to make this branch fully functional.

xref: #2213, #30243

Context

Documentation (please check one with an [x])

• I have updated the documentation, or
• No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• Code inspection only, or
• Newly added/modified unit tests, or
• No unit tests but ran on a real repository, or
• Both unit tests + ran on a real repository

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what's wrong with mkdocs 😅

no meanful error message

Aborted with 1 warnings in strict mode!
ERROR: Error occured:
       null
 ELIFECYCLE  Command failed with exit code 1.

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looks like build-docs is flaky