Remove out-of-date comment. NFC (emscripten-core#22518)

This comment may have made sense when this code was inline inside of a
for loop.

src/preamble.js

@@ -531,7 +531,6 @@ function createExportWrapper(name, nargs) {
 // to ignore exceptions from there since they're handled by callMain directly.
 var abortWrapperDepth = 0;
 
-// Creates a wrapper in a closure so that each wrapper gets it's own copy of 'original'
 function makeAbortWrapper(original) {
   return (...args) => {
     // Don't allow this function to be called if we're aborted!