fix: handle paths on different drives in Windows for zap-gui

[WangHunZi]

Fix zap-gui path handling on Windows systems with different drives

Issue

When using west zap-gui on Windows, if the ZAP file and any of the required files (ZCL or app templates) are located on different drives, the command fails with: ValueError: 'c:\\ncs\\v3.0.0-rc1\\modules\\lib\\matter\\src\\app\\zap-templates\\zcl\\zcl.json' and 'D:\\Code\\project\\src\\default_zap' have different anchors

This occurs because pathlib.Path.relative_to() method cannot compute relative paths between different drives in Windows. The issue happens in both scenarios:

1. With default ZCL path from SDK (C: drive) and project on another drive (D: drive)
2. Even when specifying a custom ZCL file with -j option, if app-templates.json remains on a different drive

Root cause

In update_zcl_in_zap() function, the code attempts to calculate relative paths using relative_to() but doesn't handle the case when paths are on different drives in Windows.

Solution

This PR fixes the issue by:

1. Adding try/except blocks to properly catch ValueError exceptions where relative_to() is called
2. Providing absolute paths as a fallback when relative paths cannot be computed

This ensures that west zap-gui works correctly on Windows regardless of drive locations while maintaining the original behavior on Linux and macOS.

Testing

Tested on Windows 11 with:

• Project on D: drive with SDK on C: drive
• Both with default ZCL path and with custom ZCL file specified via -j option

The fix also works correctly on Linux as before, where this issue doesn't occur.

[NordicBuilder]

none

Note: This comment is automatically posted and updated by the Contribs GitHub Action.

[kkasperczyk-no]

LGTM 👍 Thank you for the contribution!

[adigie]

Hi @WangHunZi, you have to sign Contributor License Agreement before we can merge this. Please force push to this PR to trigger the CLAassistant.

[CLAassistant]

All committers have signed the CLA.

[WangHunZi]

Hi @WangHunZi, you have to sign Contributor License Agreement before we can merge this. Please force push to this PR to trigger the CLAassistant.

Hi @adigie , thank you for the reminder! I've signed the CLA and addressed the requested changes. Could you please help approve the pending workflows so we can proceed? Let me know if there's anything else I need to do. Thanks again for your assistance!