Bump rubocop from 1.54.0 to 1.56.0

Bumps [rubocop](https://github.com/rubocop/rubocop) from 1.54.0 to 1.56.0.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v1.54.0...v1.56.0)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -16,6 +16,7 @@ GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.2)
+    base64 (0.1.1)
     concurrent-ruby (1.1.10)
     docopt (0.6.1)
     domain_name (0.5.20190701)
@@ -55,16 +56,17 @@ GEM
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 4.0)
       netrc (~> 0.8)
-    rexml (3.2.5)
-    rubocop (1.54.0)
+    rexml (3.2.6)
+    rubocop (1.56.0)
+      base64 (~> 0.1.1)
       json (~> 2.3)
       language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
       parser (>= 3.2.2.3)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8, < 3.0)
       rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.28.0, < 2.0)
+      rubocop-ast (>= 1.28.1, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)
     rubocop-ast (1.29.0)