transcriberbin: always cycle transcriber state on passthrough

Users may want to restart the transcriber, for instance AWS
transcribe has a 4-hour limit and it may be desirable to start a
new session before that deadline by toggling passthrough on and
immediately off.
13 jobs for !663 with transcriberbin-toggle-passthrough in 31 minutes and 13 seconds (queued for 1 second)
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