symlink removal after a fresh build

[azutechNL]

Add these changes into the build.py

This fixes the issue that the symlink are removed after a fresh build:

def link_assets_dir(source, target, hard_link=False):
if not os.path.exists(source):
return

if os.path.exists(target):
    if os.path.islink(target):
        return  
    else:
        shutil.rmtree(target)  # Deletes directory if it's not a symlink

if hard_link:
    shutil.copytree(source, target, dirs_exist_ok=True)
else:
    symlink(source, target, overwrite=True)

[akhilnarang]

Can you please raise a PR?