Avoid writing license file to root directory in Unity license script

[coderabbitai]

Writing the Unity license file to /root/.local/share/unity3d/Unity/Unity_lic.ulf assumes the script is running as root, which may not be the case. This can cause permission issues and reduce portability.

This issue was identified in PR #83 in this comment by @GabLeRoux.

We should consider updating the script to store the license file in the current user's home directory instead.