Windows: Add hardening when renaming Phar during update

[swissspidy]

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[github-actions]

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 13 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
php/commands/src/CLI_Command.php	0.00%	13 Missing ⚠️

📢 Thoughts on this report? Let us know!

[gemini-code-assist]

Code Review

This pull request introduces Windows-specific logic for updating the WP-CLI PHAR file, utilizing a backup file during the rename process to avoid potential file locking issues. Feedback was provided to improve the robustness of the realpath() call, as it can return false and result in an empty string when cast; a suggestion was made to fall back to the original path and to ensure support for tilde expansion in home-relative paths.