Build(deps-dev): Bump rubocop from 0.79.0 to 0.80.0 (#8997)

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.79.0 to 0.80.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.79.0...v0.80.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: Robin Ward <robin.ward@gmail.com>

Gemfile.lock

@@ -306,6 +306,7 @@ GEM
       redis (>= 3.0.4)
     request_store (1.5.0)
       rack (>= 1.4)
+    rexml (3.2.4)
     rinku (2.0.6)
     rotp (5.1.0)
       addressable (~> 2.5)
@@ -338,11 +339,12 @@ GEM
       rspec-support (~> 3.8)
     rspec-support (3.9.2)
     rtlit (0.0.5)
-    rubocop (0.79.0)
+    rubocop (0.80.0)
       jaro_winkler (~> 1.5.1)
       parallel (~> 1.10)
       parser (>= 2.7.0.1)
       rainbow (>= 2.2.2, < 4.0)
+      rexml
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 1.7)
     rubocop-discourse (1.0.2)