Increase multiple optimizers parity for drone CI

[SeanNaren]

What does this PR do?

Fix parity test for sharded, it seems for multiple optimisers its too tight.

Fixes #4856

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[tchaton]

LTGM !

[codecov]

Codecov Report

Merging #4884 (cbeb082) into master (597dfa1) will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #4884   +/-   ##
======================================
  Coverage      93%     93%           
======================================
  Files         121     121           
  Lines        9119    9119           
======================================
  Hits         8444    8444           
  Misses        675     675