FIXME: git integration on fedora is broken for both db repos and downloading mods

[marouamghar]

Describe the bug:
Trying to manage db repos or downloading git mods fail, with error GitCommandError: Cmd('git') failed due to: exit code(128) cmdline: git pull -v --rebase -- origin. It's able to setup the parent folder locally, and the repo origin url, but the local repo is empty.
I have git locally, running a git pull on those repos work well.

the error message is :
`The configured repo failed to update! Are you connected to the Internet? Is your configured repo valid?
Configured repository: https://github.com/bbradson/Performance-Fish
Traceback (most recent call last):
File "/home/user1/Downloads/RimSort/app/views/main_content_panel.py", line 2392, in _do_force_update_existing_repo
File "/home/user1/Downloads/RimSort/git/remote.py", line 1123, in pull
File "/home/user1/Downloads/RimSort/git/remote.py", line 895, in _get_fetch_info_from_stderr
File "/home/user1/Downloads/RimSort/git/cmd.py", line 834, in wait
git.exc.GitCommandError: Cmd('git') failed due to: exit code(128)
cmdline: git pull -v --rebase -- origin
stderr: 'fatal: Updating an unborn branch with changes added to the index.'

`

To Reproduce:
Steps to reproduce the behavior:
It fails for both db github repos (using the default ones from RimSort) and downloading a mod from github. The easiest way to repro it is to try and download performance fish.

1. Go to Download
2. Click on Add Git mod
3. Put https://github.com/bbradson/Performance-Fish
4. See error

• Operating System: [e.g. Windows 11]
• Processor Architecture: [Arm/x86/Unknown]
• RimSort version: 1.08
• Please provide a RimSort.log:
• Are you running from the Python interpreter or from a compiled RimSort release? release

Additional context:
When running RimSort through cmdline, the only weird log was :
[WARNING][2024-07-03 17:14:32][81736][MainThread][main_content_panel][_do_force_update_existing_repo][2387] : Target branch not found.