Compilation error caused by Different Drive Letter on Windows

[tanreinama]

Is your feature request related to a problem? Please describe.
The following error occurs when the project folder is located on a drive other than the C drive.

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\venv\Scripts\west.exe\__main__.py", line 7, in <module>
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\venv\Lib\site-packages\west\app\main.py", line 1199, in main
    app.run(argv or sys.argv[1:])
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\venv\Lib\site-packages\west\app\main.py", line 278, in run
    self.run_command(argv, early_args)
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\venv\Lib\site-packages\west\app\main.py", line 584, in run_command
    self.run_extension(args.command, argv)
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\venv\Lib\site-packages\west\app\main.py", line 739, in run_extension
    self.cmd.run(args, unknown, self.topdir, manifest=self.manifest,
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\venv\Lib\site-packages\west\commands.py", line 200, in run
    self.do_run(args, unknown)
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\zephyr-main\scripts\west_commands\build.py", line 263, in do_run
    self._sanity_check()
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\zephyr-main\scripts\west_commands\build.py", line 582, in _sanity_check
    self._sanity_check_source_dir()
  File "C:\Users\sakam\.pico-sdk\zephyr_workspace\zephyr-main\scripts\west_commands\build.py", line 566, in _sanity_check_source_dir
    srcrel = os.path.relpath(self.source_dir)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen ntpath>", line 796, in relpath
ValueError: path is on mount 'D:', start on mount 'C:'

Describe the solution you'd like
Works correctly regardless of drive letter

Describe alternatives you've considered
In a Windows environment, drive letters must be taken into account; therefore, a relative path cannot be created when crossing between different drives.
It seems there is an issue with the mechanism that performs compilation using relative paths, even though the workspace is set up at .pico-sdk\zephyr_workspace. Possible solutions include creating a symbolic link to the target project within .pico-sdk\zephyr_workspace before compilation and reverting it afterward.

Additional context

[will-v-pi]

This looks like an upstream Zephyr bug - I have opened a PR to fix it zephyrproject-rtos/zephyr#112122

That path is just used for the error messages below, so if you want a quick fix you can edit that build.py file with the change in that PR to fix this issue