feat: move Rust Cargo Lambda out of experimental

- Add CargoLambda to ExperimentalFlag with persistent=True
- Update is_experimental_enabled() to always return True for persistent flags
- Update unit tests for new flag count and persistent behavior

Author: bnusunny

tests/unit/commands/_utils/test_experimental.py

@@ -57,16 +57,16 @@ def test_set_experimental(self):
         self.gc_mock.return_value.set_value.assert_called_once_with(config_entry, False, is_flag=True, flush=False)
 
     def test_get_all_experimental(self):
-        self.assertEqual(len(get_all_experimental()), 4)
+        self.assertEqual(len(get_all_experimental()), 5)
 
     def test_get_all_experimental_statues(self):
-        self.assertEqual(len(get_all_experimental_statues()), 4)
+        self.assertEqual(len(get_all_experimental_statues()), 5)
 
     def test_get_all_experimental_env_vars(self):
-        self.assertEqual(len(get_all_experimental_env_vars()), 4)
+        self.assertEqual(len(get_all_experimental_env_vars()), 5)
 
     def test_get_enabled_experimental_flags(self):
-        self.assertEqual(len(get_enabled_experimental_flags()), 4)
+        self.assertEqual(len(get_enabled_experimental_flags()), 5)
 
     @patch("samcli.commands._utils.experimental.set_experimental")
     @patch("samcli.commands._utils.experimental.get_all_experimental")