gh-124113: Clarify venv target directory reuse

[harjothkhara]

Clarifies the venv docs for the case where the target directory already exists:

• an existing directory is reused, not rejected;
• reuse doesn't leave the directory untouched — venv may create, update, or replace files in it, so a dedicated directory is best;
• --clear deletes all contents of the target directory (including files venv didn't create) before creating the environment.

Docs-only, no behavior change. Per the maintainer direction in gh-135604, the intended fix here is this clarification rather than a behavior change.

Disclosure: AI-assisted wording; I've reviewed it.

• Issue: Document what happens when venv is run using existing directory #124113

[read-the-docs-community]

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1 file changed

± library/venv.html