Don't add 'rdoc' as a dependency

When dependabot opened a PR to update 'rdoc' version,
we got a few errors in Ruby https://github.com/faker-ruby/faker/actions/runs/20980245054/job/60303497935?pr=3178

The dependency was added in github.com//pull/3165
but that deprecation warning is not generated anymore after upgrading
my local ruby version to 4.0.

Removing 'rdoc' from the Gemfile does not break using faker
console and I don't see the warning anymore. And since 'rdoc' is part of Ruby 3.5
by default, we don't need to list it as a dependency. For anyone using Ruby < 3.5 when
opening a faker console, they can install 'rdoc' as needed locally.

Author: stefannibrasil

Gemfile

@@ -9,7 +9,6 @@ gem 'irb'
 gem 'minitest', '5.27.0'
 gem 'pry', '0.16.0'
 gem 'rake', '13.3.1'
-gem 'rdoc'
 gem 'rubocop', '1.82.1'
 gem 'rubocop-minitest', '0.38.2'
 gem 'rubocop-rake', '0.7.1'

Gemfile.lock

@@ -103,7 +103,6 @@ DEPENDENCIES
   minitest (= 5.27.0)
   pry (= 0.16.0)
   rake (= 13.3.1)
-  rdoc
   rubocop (= 1.82.1)
   rubocop-minitest (= 0.38.2)
   rubocop-rake (= 0.7.1)