ARROW-17891: [Docs][Python] Update and sync Win section of the developers/python page

[AlenkaF]

This PR updates Windows section of the Python Development page. Main changes:

• use Python 3.10 (also in instructions for Linux/MacOs)
• definition of PATH not needed as Python doesn't search in PATH for dlls anymore (3.8 +)
• use CONDA_PREFIX to define ARROW_HOME as in other parts of the docs
• remove Running C++ unit tests for Python integration section (C++ unit tests are part of pytest-based test module as of https://github.com/apache/arrow/pull/14117)

cc @wjones127 @jorisvandenbossche

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https://issues.apache.org/jira/browse/ARROW-17891

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[AlenkaF]

@jorisvandenbossche I think this changes would be good to have in 10.0.0. You think it is ready to get merged with ARROW_HOME=%CONDA_PREFIX% before the branch freeze?

[jorisvandenbossche]

Thanks!