Bump minitest from 5.15.0 to 5.23.1

Bumps [minitest](https://github.com/minitest/minitest) from 5.15.0 to 5.23.1.
- [Changelog](https://github.com/minitest/minitest/blob/master/History.rdoc)
- [Commits](minitest/minitest@v5.15.0...v5.23.1)

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

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

Gemfile

@@ -135,7 +135,7 @@ group :test do
   gem 'poltergeist'
 
   # Temporary lock until the flaky test issue is fixed on Minitest side that's present in 5.16.0
-  gem 'minitest', '= 5.15.0'
+  gem 'minitest', '5.23.1'
 end
 
 group :development, :test do

Gemfile.lock

@@ -200,7 +200,7 @@ GEM
     method_source (1.1.0)
     mini_mime (1.1.5)
     mini_portile2 (2.8.6)
-    minitest (5.15.0)
+    minitest (5.23.1)
     msgpack (1.7.2)
     multi_xml (0.7.1)
       bigdecimal (~> 3.1)
@@ -507,7 +507,7 @@ DEPENDENCIES
   jquery-rails
   letter_opener
   listen
-  minitest (= 5.15.0)
+  minitest (= 5.23.1)
   omniauth-rails_csrf_protection
   omniauth-zeuswpi
   paper_trail