test for Enable setting property (#15755)

Co-authored-by: thomas chaton <thomas@grid.ai>
Co-authored-by: Ethan Harris <ethanwharris@gmail.com>
(cherry picked from commit ba14038)

tests/tests_app/core/test_lightning_app.py

@@ -1114,7 +1114,6 @@ class FlowValue(LightningFlow):
     def __init__(self):
         super().__init__()
         self._value = None
-        self._has_found = False
 
     @property
     def value(self):
@@ -1125,19 +1124,13 @@ def value(self, value):
         self._value = value
 
     def run(self):
-        if self.value is None:
-            self.value = True
-
-    def __setattr__(self, name, value):
-        if name == "_value" and value is True:
-            self._has_found = True
-        super().__setattr__(name, value)
+        self.value = True
 
 
 def test_lightning_flow_properties():
     """Validates setting properties to the LightningFlow properly calls property.fset."""
 
     flow = FlowValue()
-    assert not flow._has_found
+    assert flow._value is None
     flow.run()
-    assert flow._has_found
+    assert flow._value is True