In dict return unresolved method, so it works with doctest

Author: saulshanabrook

python/egglog/runtime.py

@@ -382,7 +382,7 @@ def __getattr__(self, name: str) -> RuntimeFunction | RuntimeExpr | Callable:
 
         preserved_methods = cls_decl.preserved_methods
         if name in preserved_methods:
-            return preserved_methods[name].__get__(self)
+            return preserved_methods[name]
 
         # if this is a class variable, return an expr for it, otherwise, assume it's a method
         if name in cls_decl.class_variables: