card: fix memory leak from nested function scoping (#33328)

* stash

* no other leaks! pm.send grows memory usage by ~20mb but that's it

* undo

* clean up

selfdrive/car/card.py

@@ -66,15 +66,7 @@ def is_dataclass(obj):
   return hasattr(obj, _FIELDS)
 
 
-def asdictref(obj) -> dict[str, Any]:
+def _asdictref_inner(obj) -> dict[str, Any] | Any:
-  """
-  Similar to dataclasses.asdict without recursive type checking and copy.deepcopy
-  Note that the resulting dict will contain references to the original struct as a result
-  """
-  if not is_dataclass(obj):
-    raise TypeError("asdictref() should be called on dataclass instances")
-
-  def _asdictref_inner(obj) -> dict[str, Any] | Any:
   if is_dataclass(obj):
     ret = {}
     for field in getattr(obj, _FIELDS):  # similar to dataclasses.fields()
@@ -85,6 +77,15 @@ def asdictref(obj) -> dict[str, Any]:
   else:
     return obj
 
+
+def asdictref(obj) -> dict[str, Any]:
+  """
+  Similar to dataclasses.asdict without recursive type checking and copy.deepcopy
+  Note that the resulting dict will contain references to the original struct as a result
+  """
+  if not is_dataclass(obj):
+    raise TypeError("asdictref() should be called on dataclass instances")
+
   return _asdictref_inner(obj)