Merge pull request #218 from increments/dependabot/bundler/rubocop-tw-1.81.6

Update rubocop requirement from ~> 1.76.0 to ~> 1.81.6

Author: tsuzuki-takaaki

Gemfile

@@ -8,6 +8,6 @@ gem "bundler"
 gem "pry"
 gem "rake"
 gem "rspec", "~> 3.1"
-gem "rubocop", "~> 1.76.0"
+gem "rubocop", "~> 1.81.6"
 gem "simplecov", "!= 0.18.0", "!= 0.18.1", "!= 0.18.2", "!= 0.18.3", "!= 0.18.4", "!= 0.18.5", "!= 0.19.0", "!= 0.19.1"
 gem "simplecov_json_formatter"