Handle ImportError in xpress import

Also catch ImportError for xpress import. This should resolve rarely occuring compat problem with numpy packages

Author: FabianHofmann

linopy/solvers.py

@@ -103,7 +103,7 @@
 
     available_solvers.append("cplex")
 
-with contextlib.suppress(ModuleNotFoundError):
+with contextlib.suppress(ModuleNotFoundError,ImportError):
     import xpress
 
     available_solvers.append("xpress")