bpo-45061: Enhance faulthandler traceback wit no Python frame (GH-28090)

Fix indentation of <no Python frame> message in a faulthandler
traceback or a Fatal Python error traceback. Example:

Current thread 0x00007f03896fb740 (most recent call first):
  Garbage-collecting
  <no Python frame>
(cherry picked from commit 888d4cc06b887e77f281ba4d640e281cb4c61b7b)

Co-authored-by: Victor Stinner <vstinner@python.org>