KiCAD generates a lot of backup-like files, for example MyPCB.sch-bak that should be ignored by git and don’t need to be committed to the repository.
This is the .gitignore file I use to manage my KiCAD projects:
*-bak *-backups *-cache* *-bak* _autosave* \#auto_saved_files\#
Note that TechOverflow’s KiCAD project initialization script automatically generates this.gitignore.