don't give pycryptosat as valid subsolver

.github/workflows/python-test.yml

@@ -18,7 +18,7 @@ jobs:
           python -m pip install --upgrade pip
           pip install flake8 pytest requests pandas
           if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
-          pip install python-sat[aiger,approxmc,cryptosat,pblib]
+          pip install python-sat
           pip install z3-solver
           pip install exact
           pip install pysdd

cpmpy/solvers/pysat.py

@@ -81,7 +81,7 @@ def solvernames():
         from pysat.solvers import SolverNames
         names = []
         for name, attr in vars(SolverNames).items():
-            if not name.startswith('__') and isinstance(attr, tuple):
+            if not name.startswith('__') and isinstance(attr, tuple) and not 'crypto' in name:
                 if name not in attr:
                     name = attr[-1]
                 names.append(name)