macros: characterization tests for ? operator fail

When a `?` operator is used in a tokio entry point function (wrapped in
`#[tokio::main]`), which has a Option or Result return type, but where
the function does not actually return that type correctly, currently the
compiler returns two errors instead of just one. The first of which is
incorrect and only exists due to the macro expanding to an async block.

```
cannot use the `?` operator in an async block that returns `()`
```

This commit is a characterization test for this behavior to help show
when it's fixed (or even changed for better / worse)

tests-build/tests/fail/macros_type_mismatch.rs

@@ -23,7 +23,7 @@ async fn extra_semicolon() -> Result<(), ()> {
     Ok(());
 }
 
-/// This test is a charecterization test for the `?` operator.
+/// This test is a characterization test for the `?` operator.
 ///
 /// See <https://github.com/tokio-rs/tokio/issues/6930#issuecomment-2572502517> for more details.
 ///
@@ -40,7 +40,7 @@ async fn question_mark_operator_with_invalid_option() -> Option<()> {
     None?;
 }
 
-/// This test is a charecterization test for the `?` operator.
+/// This test is a characterization test for the `?` operator.
 ///
 /// See <https://github.com/tokio-rs/tokio/issues/6930#issuecomment-2572502517> for more details.
 ///