CompatHelper: bump compat for "Zygote" to "0.5"

[github-actions]

This pull request changes the compat entry for the Zygote package from 0.4 to 0.4, 0.5.

This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry. It is your responsibility to make sure that your package tests pass before you merge this pull request.

[codecov]

Codecov Report

Merging #233 into master will increase coverage by 0.05%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #233      +/-   ##
==========================================
+ Coverage   82.78%   82.84%   +0.05%     
==========================================
  Files          19       19              
  Lines        1900     1900              
==========================================
+ Hits         1573     1574       +1     
+ Misses        327      326       -1     

Impacted Files	Coverage Δ
src/Optimization.jl	77.90% <0.00%> (+0.11%)	⬆️

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