Added solver glpk

[V3lop5]

This PR ...

adds a solver to the docker image.

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Checklist

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• Unit tests successful

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[codecov-commenter]

Codecov Report

Merging #121 (40acb7f) into main (3ae65bf) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##             main     #121   +/-   ##
=======================================
  Coverage   79.42%   79.42%           
=======================================
  Files         104      104           
  Lines        2522     2522           
=======================================
  Hits         2003     2003           
  Misses        519      519           

Flag	Coverage Δ
pytest	79.42% <0.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
ensysmod/core/fine_esm.py	16.51% <0.00%> (ø)

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[github-actions]

Unit Test Results

    1 files  ±0      1 suites  ±0   1m 5s ⏱️ +32s
400 tests ±0  384 ✔️ ±0  16 💤 ±0  0 ❌ ±0 

Results for commit 3dcf29d. ± Comparison against base commit 3ae65bf.