ports/stm: reuse existing translations and shared deinit guard in audioio

Address review feedback on PR #10976:

- Replace 11 audioio-specific MP_ERROR_TEXT strings with existing pot
  entries via %q substitution (Invalid %q pin, %q init failed) or by
  reusing analogio/AnalogOut's "DAC Device/Channel Init Error".
- Drop the redundant in-driver deinit check in
  common_hal_audioio_audioout_play(); the shared-bindings layer already
  guards every entry point with check_for_deinit -> raise_deinited_error.
- Net result: zero new entries in locale/circuitpython.pot.
- Also remove tests/circuitpython-manual/audioio/results.md (committed
  in a prior commit; the test scripts stay, the captured run output
  shouldn't live in the repo).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>