python: subfolder_list.py now generates shorter link names
python: subfolder_list.py now generates shorter link names

Fixes: #24576

The name of the symbolic link would be constructed using the full path
name to the target folder.

This is not needed and caused the issue raised in #24576.

This has been fixed by no longer using the toplevel target directory
in the link name, for example:
Old style: _project_zephyr_workspace_zephyr_include_sys
New style: include_sys

Signed-off-by: Torsten Rasmussen <a7c5b1d5a1f41fce6edfa3f7c2392ae0c59deafe@nordicsemi.no>

finikorg/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,nashif/zephyr,Vudentz/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,Vudentz/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,nashif/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,nashif/zephyr