chore: remove stale bot

[levithomason]

Stale bot has been contentious for a lot of ppl. It has also been removed on the core repo.

[codecov-io]

Codecov Report

Merging #3858 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3858   +/-   ##
=======================================
  Coverage   99.84%   99.84%           
=======================================
  Files         177      177           
  Lines        3145     3145           
=======================================
  Hits         3140     3140           
  Misses          5        5

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