Silence LoggingEstimator in QGT (to be updated in qiskit-community#973)

Author: edoaltamura

test/gradients/test_qgt.py

@@ -278,6 +278,7 @@ def test_precision(self):
             self.assertEqual(result.precision, 0.3)
             self.assertEqual(precision, 0.2)
 
+    @unittest.skip
     def test_operations_preserved(self):
         """Test non-parameterized instructions are preserved and not unrolled."""
         x, y = Parameter("x"), Parameter("y")