Enhance readability of .python-version

[lmvysakh]

Enhance reading from .python-version file, matching the Pyenv behavior:

• Resolves multiple versions from multiple lines
• Handles pyenv-virtualenv pointers (e.g. 3.10/envs/virtualenv)
  (see Don't use .python-version for auto-activation pyenv/pyenv-virtualenv#472)
• Ignores empty lines and lines starting with #
• Trims whitespace

We extend our thanks to @krystof-k for the valuable contribution in implementing this feature in PR #787. To expedite its availability to users, we have created this PR, which incorporates the same changes while addressing the CI issues that had previously delayed the merge of PR #787.

Check list:

• Tests were added or updated to cover the changes.

[Copilot]

Pull Request Overview

This PR improves the readability and functionality when reading the .python-version file by supporting multiple versions, handling pyenv-virtualenv pointers, ignoring comments and empty lines, and trimming whitespace.

• Updated the function name and logic in utils.ts to process multiple lines.
• Refactored setup-python.ts and updated tests in tests/utils.test.ts to integrate the new behavior.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/utils.ts	Renamed and updated function to support multi-line version files and pointer handling.
src/setup-python.ts	Updated import and usage to reflect the new function name.
tests/utils.test.ts	Added tests for multi-line files and updated expected outcomes.

[Copilot]

[nitpick] Consider caching the result of line.trim() in a variable to avoid calling trim() multiple times within the mapping function.

Suggested change

	if(line.startsWith('#')||line.trim()===''){
	returnundefined;
	}
	letversion: string=line.trim();
	consttrimmedLine=line.trim();
	if(line.startsWith('#')||trimmedLine===''){
	returnundefined;
	}
	letversion: string=trimmedLine;

[lmvysakh]

The relevant changes and improvements proposed here have already been addressed and implemented in PR #787. Hence, this PR is now superseded by #787, which provides a more comprehensive solution for the scenarios discussed. Therefore, we are closing this pull request.