fix: fix ExtendedSettingsConfigDict does not work (#660)

* refactor: Replace ExtendedSettingsConfigDict with SettingsConfigDict

* lint

* lint

test/utils/test_conf.py

@@ -0,0 +1,18 @@
+import unittest
+
+
+class ConfUtils(unittest.TestCase):
+
+    def test_conf(self):
+        import os
+
+        from rdagent.utils.env import QlibDockerConf
+
+        os.environ["MEM_LIMIT"] = "200g"
+        assert QlibDockerConf().mem_limit == "200g"  # base class will affect subclasses
+        os.environ["QLIB_DOCKER_MEM_LIMIT"] = "300g"
+        assert QlibDockerConf().mem_limit == "300g"  # more accurate subclass will override the base class
+
+
+if __name__ == "__main__":
+    unittest.main()