Bump rubocop from 1.54.2 to 1.56.4

Bumps [rubocop](https://github.com/rubocop/rubocop) from 1.54.2 to 1.56.4.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v1.54.2...v1.56.4)

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

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

Gemfile.lock

@@ -2,6 +2,7 @@ GEM
   remote: http://rubygems.org/
   specs:
     ast (2.4.2)
+    base64 (0.1.1)
     childprocess (4.1.0)
     codecov (0.6.0)
       simplecov (>= 0.15, < 0.22)
@@ -67,7 +68,7 @@ GEM
     rainbow (3.1.1)
     rake (13.0.6)
     regexp_parser (2.8.1)
-    rexml (3.2.5)
+    rexml (3.2.6)
     rspec (3.12.0)
       rspec-core (~> 3.12.0)
       rspec-expectations (~> 3.12.0)
@@ -81,15 +82,16 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.12.0)
     rspec-support (3.12.1)
-    rubocop (1.54.2)
+    rubocop (1.56.4)
+      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)