chore: Fix PR 7510 (#7513)

Author: VaggelisD

tests/dialects/test_mysql.py

@@ -1685,11 +1685,7 @@ def test_ignore_respect_nulls(self):
 
     def test_invisible_column(self):
         expr = self.parse_one("CREATE TABLE t (c INT INVISIBLE)")
-        self.assertIsNotNone(
-            expr.find(exp.InvisibleColumnConstraint)
-        )
+        self.assertIsNotNone(expr.find(exp.InvisibleColumnConstraint))
 
         expr = self.parse_one("ALTER TABLE t ADD COLUMN c INT INVISIBLE")
-        self.assertIsInstance(
-            expr.find(exp.InvisibleColumnConstraint)
-        )
+        self.assertIsNotNone(expr.find(exp.InvisibleColumnConstraint))