repo-updater: remove updateScheduler mutex

Created by: keegancsmith

As far as I can tell this mutex serves no purpose. The only possible purpose is to serialize calls to UpdateFromDiff. However, the individual upsert and remove calls on the scheduler and queue have there own mutexes.

Possibly if we had two concurrent UpdateFromDiff we could have an inconsistent state, but it would converge at the next UpdateFromDiff call. Additionally we only have one call site for UpdateFromDiff, and that never runs concurrently.

Created by: codecov[bot]

Codecov Report

Merging #11632 into master will decrease coverage by 0.00%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #11632      +/-   ##
==========================================
- Coverage   47.53%   47.53%   -0.01%     
==========================================
  Files        1402     1402              
  Lines       79473    79471       -2     
  Branches     6775     6775              
==========================================
- Hits        37777    37775       -2     
  Misses      38122    38122              
  Partials     3574     3574              

Flag	Coverage Δ
#go	51.73% <ø> (-0.01%)
#storybook	10.12% <ø> (ø)
#typescript	36.42% <ø> (ø)
#unit	47.13% <ø> (-0.01%)

Impacted Files	Coverage Δ
cmd/repo-updater/repos/scheduler.go	63.42% <ø> (-0.21%)