Don't run tests which fail to compile

Co-authored-by: Alice Ryhl <alice@ryhl.io>

tokio/src/process/mod.rs

@@ -843,7 +843,8 @@ pub struct Child {
     /// yourself from calling functions on `child` while using `stdin`, you might
     /// find it helpful to do:
     ///
-    /// ```compile_fail,E0425
+    /// ```no_run
+    /// # let child: tokio::process::Child = unreachable!();
     /// let stdin = child.stdin.take().unwrap();
     /// ```
     pub stdin: Option<ChildStdin>,