Revert "Temporarily use a non-default branch of cisagov/ansible-role-upgrade"

This reverts commit c3f374c18f7c83705a0f98849c21c0d69f0925fc.

The non-default branch of cisagov/ansible-role-upgrade that we were
using was merged into the default branch in
cisagov/ansible-role-upgrade#55.

Author: jsf9k

molecule/default/requirements.yml

@@ -1,4 +1,3 @@
 ---
 - src: https://github.com/cisagov/ansible-role-upgrade
   name: upgrade
-  version: improvement/use-detected-package-manager