doc: edit text for DEP0012

Fix awkward verb tense.

PR-URL: #20519
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

doc/api/deprecations.md

@@ -161,7 +161,7 @@ instead.
 
 Type: End-of-Life
 
-`Domain.dispose()` is removed. Recover from failed I/O actions
+`Domain.dispose()` has been removed. Recover from failed I/O actions
 explicitly via error event handlers set on the domain instead.
 
 <a id="DEP0013"></a>