Fix matrix variable test assertions to use getVal

Updated assertions in test_matrix_variable.py to use m.getVal(x) and m.getVal(y) instead of direct variable comparison. This ensures the tests check the evaluated values from the model rather than the symbolic variables.

Author: Zeroto521

tests/test_matrix_variable.py

@@ -428,8 +428,8 @@ def test_matrix_cons_compare_with_expr():
 
     m.setObjective(x.sum() + y.sum())
 
-    assert (x == np.ones(3)).all()
-    assert (y == np.ones(3)).all()
+    assert (m.getVal(x) == np.ones(3)).all()
+    assert (m.getVal(y) == np.ones(3)).all()
 
 
 def test_ranged_matrix_cons():
@@ -446,4 +446,4 @@ def test_ranged_matrix_cons():
 
     m.setObjective(x.sum())
 
-    assert (x == np.ones(3)).all()
+    assert (m.getVal(x) == np.ones(3)).all()