fix: ambiguous associated item in forward_to_deserialize_any!

[aatifsyed]

Hit in serde-save, the following code fails to compile:

enum Value {
    Error,
}

impl<'de> serde::Deserializer<'de> for Value {
    type Error = serde::de::value::Error;
    fn deserialize_any<V>(self, _: V) -> Result<V::Value, serde::de::value::Error>
    where
        V: serde::de::Visitor<'de>,
    {
        todo!()
    }
    serde::forward_to_deserialize_any! {
        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
        bytes byte_buf option unit unit_struct newtype_struct seq tuple
        tuple_struct map struct enum identifier ignored_any
    }
}

error: ambiguous associated item
   --> src/lib.rs:16:5
    |
16  | /     serde::forward_to_deserialize_any! {
17  | |         bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
18  | |         bytes byte_buf option unit unit_struct newtype_struct seq tuple
19  | |         tuple_struct map struct enum identifier ignored_any
20  | |     }
    | |_____^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #57644 <https://github.com/rust-lang/rust/issues/57644>
note: `Error` could refer to the variant defined here
   --> src/lib.rs:5:5
    |
5   |     Error,
    |     ^^^^^
note: `Error` could also refer to the associated type defined here
   --> /playground/.cargo/registry/src/index.crates.io-6f17d22bba15001f/serde-1.0.197/src/de/mod.rs:911:5
    |
911 |     type Error: Error;
    |     ^^^^^^^^^^^^^^^^^
    = note: `#[deny(ambiguous_associated_items)]` on by default
    = note: this error originates in the macro `forward_to_deserialize_any_method` which comes from the expansion of the macro `serde::forward_to_deserialize_any` (in Nightly builds, run with -Z macro-backtrace for more info)

playground link

[dtolnay]

Published in serde 1.0.199.