[3.11] Update name in acknowledgements and add mailmap (GH-103696) (#…

…104002)

Update name in acknowledgements and add mailmap (GH-103696)

I changed my name last year, and would like to update my name in the
acknowledgements and git history accordingly.

git-mailmap reference: https://git-scm.com/docs/gitmailmap

(cherry picked from commit 4b10ecc)

Co-authored-by: Amethyst Reese <amethyst@n7.gg>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

.mailmap

@@ -0,0 +1,3 @@
+# This file sets the canonical name for contributors to the repository.
+# Documentation: https://git-scm.com/docs/gitmailmap
+Amethyst Reese <amethyst@n7.gg> <john@noswap.com>

Misc/ACKS

@@ -1469,7 +1469,7 @@ Marc Recht
 John Redford
 Terry J. Reedy
 Gareth Rees
-John Reese
+Amethyst Reese
 Steve Reeves
 Lennart Regebro
 John Regehr