librem5-gnome: Add libcanberra-pulse

This is needed to make ringtones work.
Status Job ID Name Coverage
  Build
failed #4056
build

 
  Test
skipped #4058
allowed to fail
code_quality
skipped #4057
test
 
Name Stage Failure
failed
build Build There has been a timeout failure or the job got stuck. Check your timeout limits or try again
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