Adding tumbl3w33d as second maintainer of maven_artifact module (#27769)

.github/BOTMETA.yml

@@ -510,7 +510,7 @@ files:
   $modules/packaging/language/cpanm.py:
   $modules/packaging/language/easy_install.py: mattupstate
   $modules/packaging/language/gem.py: $team_ansible
-  $modules/packaging/language/maven_artifact.py: chrisisbeef
+  $modules/packaging/language/maven_artifact.py: chrisisbeef tumbl3w33d
   $modules/packaging/language/npm.py:
     ignored: chrishoffman
     maintainers: shane-walker