[3.9] Become a CODEOWNER for typing (GH-31374) (GH-31381)

(cherry picked from commit 6f1efd1)


Co-authored-by: Jelle Zijlstra <[email protected]>

Automerge-Triggered-By: GH:JelleZijlstra

Author: miss-islington

.github/CODEOWNERS

@@ -111,7 +111,7 @@ Include/pytime.h              @pganssle @abalkin
 
 **/*idlelib*                  @terryjreedy
 
-**/*typing*                   @gvanrossum @Fidget-Spinner
+**/*typing*                   @gvanrossum @Fidget-Spinner @JelleZijlstra
 
 **/*asyncore                  @giampaolo
 **/*asynchat                  @giampaolo