Rollup merge of #64851 - Mark-Simulacrum:mailmap-update, r=varkor

Add mailmap entry for Dustin Bensing by request

This should deduplicate entries from @pythoneer between the stdarch submodule and this repo itself on thanks.rust-lang.org.

.mailmap

@@ -69,6 +69,7 @@ David Manescu <[email protected]> <[email protected]>
 David Ross <[email protected]>
 Derek Chiang <[email protected]> Derek Chiang (Enchi Jiang) <[email protected]>
 Diggory Hardy <[email protected]> Diggory Hardy <[email protected]>
+Dustin Bensing <[email protected]>
 Dylan Braithwaite <[email protected]> <[email protected]>
 Dzmitry Malyshau <[email protected]>
 E. Dunham <[email protected]> edunham <[email protected]>