Remove unused F.as_mql()

Author: WaVEV

django_mongodb_backend/expressions.py

@@ -13,7 +13,6 @@
     Exists,
     ExpressionList,
     ExpressionWrapper,
-    F,
     NegatedExpression,
     OrderBy,
     RawSQL,
@@ -94,10 +93,6 @@ def expression_wrapper(self, compiler, connection):
     return self.expression.as_mql(compiler, connection)
 
 
-def f(self, compiler, connection):  # noqa: ARG001
-    return f"${self.name}"
-
-
 def negated_expression(self, compiler, connection):
     return {"$not": expression_wrapper(self, compiler, connection)}
 
@@ -220,7 +215,6 @@ def register_expressions():
     Exists.as_mql = exists
     ExpressionList.as_mql = process_lhs
     ExpressionWrapper.as_mql = expression_wrapper
-    F.as_mql = f
     NegatedExpression.as_mql = negated_expression
     OrderBy.as_mql = order_by
     Query.as_mql = query