Make DegeneracyHunter tests more robust wrt different solutions

[lbianchi-lbl]

Summary/Motivation

Make DegeneracyHunter tests more robust wrt different solutions, which were previously causing issues due to differences between AMPL SCIP versions.

Changes proposed in this PR

• Apply @andrewlee94's changes from edb038b without the rest of the testing infrastructure from Test model diagnostics using multiple AMPL SCIP versions #1359
• Revert the temporary fix in Pin ampl-module-scip version to 20240121 #1354 by setting a default input value where the ampl-module-scip version is not specified exactly

Legal Acknowledgement

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1. I agree my contributions are submitted under the license terms described in the LICENSE.txt file at the top level of this directory.
2. I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.59%. Comparing base (9de79c6) to head (4164b98).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1360      +/-   ##
==========================================
- Coverage   77.60%   77.59%   -0.01%     
==========================================
  Files         391      391              
  Lines       64330    64330              
  Branches    14244    14244              
==========================================
- Hits        49923    49920       -3     
- Misses      11831    11835       +4     
+ Partials     2576     2575       -1     

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