scrobbler: Deduplicate Last.fm API calls

Move the two similar request calls (scrobble & now playing) into one.
4 jobs for wip/mschraal/goa-music-disabled in 22 minutes and 18 seconds (queued for 21 minutes and 49 seconds)
Status Job ID Name Coverage
  Check
passed #7136
pep8

00:05:04

passed #7135
pyflakes

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  Build
passed #7142
build

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failed #7137
build

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