Remove unneeded Sync context bound

[fthomas]

No description provided.

[codecov]

Codecov Report

Merging #543 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #543   +/-   ##
=======================================
  Coverage   55.74%   55.74%           
=======================================
  Files          64       64           
  Lines         809      809           
  Branches       34       34           
=======================================
  Hits          451      451           
  Misses        358      358

Impacted Files	Coverage Δ
...teward/core/github/http4s/Http4sGitHubApiAlg.scala	66.66% <ø> (ø)	⬆️

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