Changes

OBS: sync_obs_projects: fix for OSC 1.12.1

Since the Docker image used by sync_obs_projects was changed from Debian
12 to 13, several "osc" commands have in their output:

  fatal: not a git repository (or any of the parent directories): .git

Work around this by switching to the temp directory and initializing a
git repository there, with an "origin" remote that osc also expects to
exist.

Fixes: 6ac535b8 ("OBS: set default distro to debian 13")
Change-Id: I1236a065e2998fb46343df3968f7bb4dabeea55a