chore(deps): update dependency rubocop-rails to v2.21.1

Gemfile.lock

@@ -69,6 +69,7 @@ GEM
     addressable (2.8.5)
       public_suffix (>= 2.0.2, < 6.0)
     ast (2.4.2)
+    base64 (0.1.1)
     bootsnap (1.16.0)
       msgpack (~> 1.2)
     buftok (0.3.0)
@@ -209,7 +210,7 @@ GEM
       thread_safe (~> 0.3, >= 0.3.1)
     method_source (1.0.0)
     mini_mime (1.1.5)
-    minitest (5.19.0)
+    minitest (5.20.0)
     msgpack (1.6.1)
     multi_json (1.15.0)
     multipart-post (2.3.0)
@@ -243,7 +244,7 @@ GEM
     public_suffix (5.0.3)
     puma (6.3.1)
       nio4r (~> 2.0)
-    racc (1.6.2)
+    racc (1.7.1)
     rack (2.2.8)
     rack-test (2.1.0)
       rack (>= 1.3)
@@ -309,20 +310,21 @@ GEM
     rspec-support (3.12.0)
     rspec_junit_formatter (0.6.0)
       rspec-core (>= 2, < 4, != 2.12.0)
-    rubocop (1.53.0)
+    rubocop (1.56.3)
+      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)
       parser (>= 3.2.1.0)
-    rubocop-rails (2.20.2)
+    rubocop-rails (2.21.1)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.33.0, < 2.0)