Use incoherent instances for ToSym and ToCon

[lsrcz]

This pull request annotates the ToSym a (UnionM b) and ToCon (UnionM a) b instances as incoherent. This could make GHC happy in more generic environment.

The instances should be effectively coherent.

[codecov]

Codecov Report

Base: 32.65% // Head: 32.63% // Decreases project coverage by -0.03% ⚠️

Coverage data is based on head (d74c275) compared to base (48089ac).
Patch has no changes to coverable lines.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #54      +/-   ##
==========================================
- Coverage   32.65%   32.63%   -0.03%     
==========================================
  Files          48       48              
  Lines        4526     4526              
  Branches      215      216       +1     
==========================================
- Hits         1478     1477       -1     
  Misses       2833     2833              
- Partials      215      216       +1     

Impacted Files	Coverage Δ
src/Grisette/Core/Control/Monad/UnionM.hs	11.17% <ø> (ø)
...c/Grisette/IR/SymPrim/Data/Prim/PartialEval/Num.hs	86.81% <0.00%> (-1.10%)	⬇️
.../Grisette/IR/SymPrim/Data/Prim/PartialEval/Bool.hs	86.66% <0.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.