Creating a lock now uses python built-in "open()" method to work arou…

…nd docker virtiofs issue

git/util.py

@@ -935,11 +935,7 @@ def _obtain_lock_or_raise(self) -> None:
             )
 
         try:
-            flags = os.O_WRONLY | os.O_CREAT | os.O_EXCL
-            if is_win:
-                flags |= os.O_SHORT_LIVED
-            fd = os.open(lock_file, flags, 0)
-            os.close(fd)
+            open(lock_file, mode='w', closefd=True)
         except OSError as e:
             raise IOError(str(e)) from e