Fix IIS interface for current CPLEX releases

[jsiirola]

Fixes # .

Summary/Motivation:

This PR fixes the interface for computing the IIS through CPLEX. Apparently, current versions of CPLEX (starting in 22.1.2.1) require passing the list of constraints to consider when calling conflict.refine() [this interface is poorly documented, and the examples that the documentation references apparently are not available unless you install CPLEX studio]. Based on the refine() docstring, adding conflict.all_constraints() as the sole argument appears to work (tested back through cplex 22.1.1.0).

Changes proposed in this PR:

• Pass conflict.all_constraints() as the sole argument for conflict.refine()
• Remove restriction disallowing recent CPLEX versions in the GHA test driver

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[blnicho]

Looks good pending tests

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.17%. Comparing base (984f242) to head (5643fb7).
⚠️ Report is 40 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3965      +/-   ##
==========================================
+ Coverage   90.10%   90.17%   +0.06%     
==========================================
  Files         909      909              
  Lines      108551   109317     +766     
==========================================
+ Hits        97813    98577     +764     
- Misses      10738    10740       +2     

Flag	Coverage Δ
builders	29.09% <0.00%> (+<0.01%)	⬆️
default	86.10% <0.00%> (?)
expensive	35.12% <0.00%> (?)
linux	87.62% <100.00%> (-1.99%)	⬇️
linux_other	87.62% <100.00%> (+<0.01%)	⬆️
oldsolvers	28.05% <0.00%> (+<0.01%)	⬆️
osx	83.05% <100.00%> (-0.02%)	⬇️
win	85.37% <100.00%> (-0.01%)	⬇️

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