fix(codecov): leave eval()'d code out of coverage

[roxblnfk]

🔍 What was changed

• Coverage no longer lists code without a file of its own (eval()'d code, runtime-created functions, assert/regexp code, stdin, vfs://) or any path missing on disk as a source file. Both Xdebug and PCOV drivers drop these entries; the is_file() result is cached per path for the whole run.
• Before, Xdebug reported Foo.php(64) : eval()'d code under the src prefix, so it reached every report: on Windows the coverage-xml file became an NTFS alternate data stream, and Infection failed with "Could not find the source file".

Checklist

• How was this tested:
  • Tested manually: reproduced with Xdebug 3.4 on Windows, the pseudo-file is gone after the fix
  • Unit tests added
  • PCOV not checked, the filter there is defensive

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
plugin/codecov/src/Internal/Driver/PcovDriver.php	0.00%	1 Missing ⚠️
plugin/codecov/src/Internal/Driver/PseudoFile.php	85.71%	1 Missing ⚠️
...lugin/codecov/src/Internal/Driver/XdebugDriver.php	0.00%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!