message: add `#[track_caller]` to test wrapper
  this makes it easier to identify what test failed, pointing to the caller of wrapper instead of the wrapper fn
  ```
  panicked at 'the test failed', src/web/rustdoc.rs:line:col
  ```
diff: @@ -20,6 +20,7 @@ use reqwest::{
  use std::{fs, net::SocketAddr, panic, sync::Arc, time::Duration};
  use tokio::runtime::Runtime;
  +#[track_caller]
  pub(crate) fn wrapper(f: impl FnOnce(&TestEnvironment) -> Result<()>) {
  let env = TestEnvironment::new();
  // if we didn't catch the panic, the server would hang forever
  