PEP 661: Update (#4923)

Author: JelleZijlstra

.github/CODEOWNERS

@@ -540,7 +540,7 @@ peps/pep-0657.rst  @pablogsal @isidentical @ammaraskar
 peps/pep-0658.rst  @brettcannon
 peps/pep-0659.rst  @markshannon
 peps/pep-0660.rst  @pfmoore
-peps/pep-0661.rst  @taleinat
+peps/pep-0661.rst  @taleinat @JelleZijlstra
 peps/pep-0662.rst  @brettcannon
 peps/pep-0662/     @brettcannon
 peps/pep-0663.rst  @ethanfurman