Remove literal_eval compatibility

jedi/_compatibility.py

@@ -204,13 +204,6 @@ except ImportError:
     import __builtin__ as builtins  # noqa: F401
 
 
-import ast  # noqa: F401
-
-
-def literal_eval(string):
-    return ast.literal_eval(string)
-
-
 def utf8_repr(func):
     """
     ``__repr__`` methods in Python 2 don't allow unicode objects to be