[FEAT] Set correct rights when install flutter

[Fizcko]

Is this a new feature request?

• I have searched the existing issues

Name of mod

mods:code-server-flutter

Wanted change

When use custom uid (PUID) and/or gid (PGID), flutter's files are installed as root

Reason for change

If we set custom uid (PUID) and/or gid (PGID) we are unable to use flutter

Proposed code change

No response

[LinuxServer-CI]

This issue has been automatically marked as stale because it has not had recent activity. This might be due to missing feedback from OP. It will be closed if no further activity occurs. Thank you for your contributions.