timers: cleanup no-longer relevant TODOs in timers/promises

PR-URL: #46499
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

lib/timers/promises.js

@@ -70,10 +70,8 @@ function setTimeout(after, value, options = kEmptyObject) {
         'boolean',
         ref));
   }
-  // TODO(@jasnell): If a decision is made that this cannot be backported
-  // to 12.x, then this can be converted to use optional chaining to
-  // simplify the check.
-  if (signal && signal.aborted) {
+
+  if (signal?.aborted) {
     return PromiseReject(new AbortError(undefined, { cause: signal.reason }));
   }
   let oncancel;
@@ -113,10 +111,8 @@ function setImmediate(value, options = kEmptyObject) {
         'boolean',
         ref));
   }
-  // TODO(@jasnell): If a decision is made that this cannot be backported
-  // to 12.x, then this can be converted to use optional chaining to
-  // simplify the check.
-  if (signal && signal.aborted) {
+
+  if (signal?.aborted) {
     return PromiseReject(new AbortError(undefined, { cause: signal.reason }));
   }
   let oncancel;