CI: install openssl from conda-forge before gamspy in test-agnostic job (#615)

* CI: install openssl from conda-forge before gamspy in test-agnostic job

Recent gamspy_base releases link against OpenSSL 3.2+, but the
ubuntu-latest runner ships OpenSSL 3.0.x (Ubuntu 22.04), causing
a runtime failure:

  GamsException: Could not load libjoatdclib64.so:
    version 'OPENSSL_3.2.0' not found

Installing openssl from conda-forge puts a new enough libssl.so.3
on the conda LD_LIBRARY_PATH before gamspy is installed, satisfying
the versioned-symbol requirement and unblocking all open PRs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* CI: also set LD_LIBRARY_PATH so conda's OpenSSL takes priority

conda does not automatically add its lib dir to LD_LIBRARY_PATH, so
the system linker still found the system libssl.so.3 (OpenSSL 3.0.x)
first, even after installing a newer openssl from conda-forge.
Exporting CONDA_PREFIX/lib at the front of LD_LIBRARY_PATH ensures
the conda-forge OpenSSL (which provides OPENSSL_3.2.0) is found
before the system one when gamspy loads its native shared library.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: DLWoodruff

.github/workflows/test_pr_and_main.yml

@@ -538,6 +538,8 @@ jobs:
           pip install numpy packaging
           python -m pip install amplpy --upgrade
           python -m amplpy.modules install highs cbc gurobi
+          conda install -c conda-forge openssl
+          echo "LD_LIBRARY_PATH=${CONDA_PREFIX}/lib:${LD_LIBRARY_PATH:-}" >> $GITHUB_ENV
           python -m pip install gamspy
           python -m pip install mip
           # license?