rust-analyzer version: (eg. output of "rust-analyzer: Show RA Version" command, accessible in VSCode via Ctrl/⌘+Shift+P)
VSC: rust-analyzer version: 0.3.1924-standalone
rust-analyzer --version: rust-analyzer 1.77.0 (aedd173 2024-03-17)

rustc version: (eg. output of rustc -V)
rustc 1.77.0 (aedd173a2 2024-03-17)

editor or extension: (eg. VSCode, Vim, Emacs, etc. For VSCode users, specify your extension version; for users of other editors, provide the distribution if applicable)
both VSCodium

Version: 1.87.2
Release: 24072
Commit: f7ed6417a7cfae92f98129384c13b505bb9cfc53
Date: 2024-03-12T18:30:28.994Z
Electron: 27.3.2
ElectronBuildId: undefined
Chromium: 118.0.5993.159
Node.js: 18.17.1
V8: 11.8.172.18-electron.0
OS: Linux x64 5.15.0-102-generic

and helix 24.3 (2cadec0b)

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

repository link (if public, optional): (eg. rust-analyzer)

code snippet to reproduce:

#[allow(unused_variables)]
#[tokio::main]
async fn main() {
    // indicates impl Future<Output = i32>
    let a1 = async { 8 };
    let a2 = async {
        return 8; // indicates a impl Future<Output = !>
    };
    let a3 = async {
        loop {
            return 8;
        } // suddenly fine impl Future<Output = i32>
    };

    let t1 = tokio::spawn(async {
        return 8; // indicates a JoinHandle<!>
    });
    let t2 = tokio::task::spawn_blocking(|| {
        return 8; // this is as expected JoinHandle<i32>
    });
}

Despite hintng Future<Output = !> and JoinHandle<!> the futures actually return correctly the value. Just the hint is incorrect.
Btw I am not a fan of writing explicitly return within async blocks, but if the compiler supports it, the hints should be correct as well.

scrnshot with hints: