stream.segmented: join worker+writer on close (#4517)
stream.segmented: join worker+writer on close (#4517)

Co-authored-by: bastimeyer <1d6e1cf70ec6f9ab28d3ea4b27a49a77654d370e@bastimeyer.de>
bastimeyer/streamlink,bastimeyer/streamlink,gravyboat/streamlink,chhe/streamlink,gravyboat/streamlink,chhe/streamlink,streamlink/streamlink,streamlink/streamlink