PATHEXT not working as expected

### Windows Terminal version

1.20.11781.0

### Windows build number

10.0.22631.3880

### Other Software

_No response_

### Steps to reproduce

Using cmd.exe
Create a shortcut to "C:\Program Files\7-Zip\7z.exe" in C:\Shims\7z.exe.lnk
Add C:\Shims to PATH - set PATH=%PATH%;C:\Shims
Add .exe.lnk to PATHEXT - set PATHEXT=%PATHEXT%;.exe.lnk
execute "7z"

### Expected Behavior

7z should execute.
This works on Windows 10 but doesn't work on Windows 11.
Also "where 7z" works correctly on both Windows 10 and Windows 11.

### Actual Behavior

'7z' is not recognized as an internal or external command,
operable program or batch file.

Start by reproducing the PATHEXT and PATH setup in cmd.exe on the reported Windows 10 and Windows 11 builds, comparing `7z`, the `7z.exe.lnk` shortcut, and `where 7z`. Done means explaining or correcting why command execution differs so that `7z` runs through the `.exe.lnk` PATHEXT entry on Windows 11.

Written by the indexing model from the issue text.