Bump minitest version (#2889)

* Bump minitest version

I got confused with dependabot's PR for minitest not containing any
release notes. Something must have changed for dependabot to not pick them
up anymore.

This error seems to be fixed in a recent minitest release:
https://github.com/minitest/minitest/blob/master/History.rdoc#5210--2024-01-11-

* Make Rubocop happy

gem dependencies were not ordered alphabetically.

* Fix Gemfile.lock merge conflict issue

Gemfile

@@ -6,7 +6,7 @@ source 'https://rubygems.org'
 gemspec
 
 gem 'benchmark'
-gem 'minitest', '5.20.0'
+gem 'minitest', '5.21.1'
 gem 'pry', '0.14.2'
 gem 'rake', '13.1.0'
 gem 'rubocop', '1.59.0'

Gemfile.lock

@@ -17,9 +17,9 @@ GEM
     json (2.7.1)
     language_server-protocol (3.17.0.3)
     method_source (1.0.0)
-    minitest (5.20.0)
+    minitest (5.21.1)
     parallel (1.24.0)
-    parser (3.3.0.2)
+    parser (3.3.0.3)
       ast (~> 2.4.1)
       racc
     power_assert (2.0.3)
@@ -63,12 +63,12 @@ GEM
     yard (0.9.34)
 
 PLATFORMS
-  ruby
+  arm64-darwin-22
 
 DEPENDENCIES
   benchmark
   faker!
-  minitest (= 5.20.0)
+  minitest (= 5.21.1)
   pry (= 0.14.2)
   rake (= 13.1.0)
   rubocop (= 1.59.0)