fix: Don't check for matching sync/async function type

[timfish]

As reported by @bizob2828,

The AST walker was only instrumenting a function when the sync/async matched the instrumentation. However, this stopped non-async functions that return a promise from being instrumented with tracePromise:

function some() {
  return Promise.resolve(42);
}

Since you can't have multiple functions with the same name, this check is not required.

[jsumners-nr]

(stamp) Looks good to me.

[bizob2828]

code and test updates look good, I'm just going to double check with my work I've been doing

[bizob2828]

this update works with the use case I originally reported