doc: use _can_ to describe actions in quic.md

Per Microsoft style guide:

> When ability is what you need to express, it's OK to use _can_ to
> describe actions or tasks that the reader or program is able to do.
> Use _might_ to express possibility. Don't use _may_, which might be
> interpreted as providing permission.

Refs: https://docs.microsoft.com/en-us/style-guide/a-z-word-list-term-collections/c/can-may
Refs: #34353 (comment)

PR-URL: #34613
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>

doc/api/quic.md

@@ -1388,7 +1388,7 @@ server.listen();
 
 The `'session'` event will be emitted multiple times.
 
-The `'session'` event handler *may* be an async function.
+The `'session'` event handler can be an async function.
 
 If the `'session'` event handler throws an error, or if it returns a `Promise`
 that is rejected, the error will be handled by destroying the `QuicServerSession`