Pin public_suffix to satisfy ruby 3.1 dependencies

Author: stefannibrasil

Gemfile

@@ -20,6 +20,7 @@ gem 'yard', '0.9.38'
 
 # TODO: remove when Ruby 3.1 is no longer supported
 gem 'erb', '~> 4.0.4'
+gem 'public_suffix', '~> 6.0.2'
 
 group :benchmark do
   gem 'benchmark'

Gemfile.lock

@@ -54,7 +54,7 @@ GEM
     psych (5.3.1)
       date
       stringio
-    public_suffix (7.0.5)
+    public_suffix (6.0.2)
     racc (1.8.1)
     rainbow (3.1.1)
     rake (13.3.1)
@@ -116,6 +116,7 @@ DEPENDENCIES
   irb
   minitest (= 5.27.0)
   pry (= 0.16.0)
+  public_suffix (~> 6.0.2)
   rake (= 13.3.1)
   rdoc
   rubocop