Don't autofill trait bound for associated type on `impl`

[KSXGitHub]

Steps to reproduce

1. Write an impl of a trait that has associated type with trait bound (e.g. Deref) for a custom type.

impl std::ops::Deref for MyType {
    // <-- place the text cursor here
}

2. Start typing "type" until the autocomplete menu with type Output = appears.
3. Choose type Output = and press Enter.

Expected behavior

It generates type Output =.

Actual behavior

It generates type Output: ?Size =, which is an invalid syntax for an impl.

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rust-analyzer version: rust-analyzer version: 0.3.1325-standalone

rustc version: rustc 1.66.0 (69f9c33d7 2022-12-12)

relevant settings: (eg. client settings, or environment variables like CARGO, RUSTUP_HOME or CARGO_HOME)