Possibly missing lint: `"some text".to_string().as_str()`

What it does

Catches instances where you use as_str() directly after to_string():

fn main() {
    // This doesn't get linted by clippy, but it seems like it should?
    println!("{}", "🧑‍🚀It's a str? Always has been 🔫🧑‍🚀".to_string().as_str());
}

playground link

And possibly also offers an auto-fix for this (just removing both method calls):

fn main() {
    // This doesn't get linted by clippy, but it seems like it should?
    println!("{}", "🧑‍🚀It's a str? Always has been 🔫🧑‍🚀");
}

Advantage

This isn't exactly something that you'd likely write verbatim, but I had it come up after a number of edits and simplifications where initially the to_string and then the as_str were justified, but after removing a bunch of format!s the code was simplified down. I was kinda surprised to see that clippy didn't tidy this up for me (usually it's really good at this sorta thing!).

The original code was something like:

function_that_expects_a_str(format!("some string with a variable: {}", var).as_str());

but then I no longer needed to use a variable, so removed it:

function_that_expects_a_str(format!("some string without a variable").as_str());

At which point clippy noted I shouldn't use format!, and it got replaced with a to_string():

function_that_expects_a_str("some string without a variable".to_string().as_str());

And thus we're left with .to_string().as_str()

Drawbacks

It's definitely a small ask, and I don't imagine it would come up very often. But given that clippy's lints got me to this place, it seems a bit weird that I should be going in to manually tidy things up afterwards.

Example

fn main() {
    println!("{}", "🧑‍🚀It's a str? Always has been 🔫🧑‍🚀".to_string().as_str());
}

Could be written as:

fn main() {
    println!("{}", "🧑‍🚀It's a str? Always has been 🔫🧑‍🚀");
}

No implementation file or test is named. Start by locating the relevant Clippy lint implementation and its tests, then use the Rust examples to define the pattern; done means the redundant .to_string().as_str() form is diagnosed and its intended simplified form is covered by tests.