Remove links to older guide versions from index page.

As older versions can now be selected with the dropdown version selector
there is no need to link to unsupported versions on the guides homepage
above the fold.

Author: p8

guides/source/_welcome.html.erb

@@ -14,21 +14,3 @@
   These guides are designed to make you immediately productive with Rails, and to help you understand how all of the pieces fit together.
 </p>
 <% end %>
-<p>
-The guides for earlier releases:
-<a href="https://guides.rubyonrails.org/v7.2/" data-turbo="false">Rails 7.2</a>,
-<a href="https://guides.rubyonrails.org/v7.1/" data-turbo="false">Rails 7.1</a>,
-<a href="https://guides.rubyonrails.org/v7.0/" data-turbo="false">Rails 7.0</a>,
-<a href="https://guides.rubyonrails.org/v6.1/" data-turbo="false">Rails 6.1</a>,
-<a href="https://guides.rubyonrails.org/v6.0/" data-turbo="false">Rails 6.0</a>,
-<a href="https://guides.rubyonrails.org/v5.2/" data-turbo="false">Rails 5.2</a>,
-<a href="https://guides.rubyonrails.org/v5.1/" data-turbo="false">Rails 5.1</a>,
-<a href="https://guides.rubyonrails.org/v5.0/" data-turbo="false">Rails 5.0</a>,
-<a href="https://guides.rubyonrails.org/v4.2/" data-turbo="false">Rails 4.2</a>,
-<a href="https://guides.rubyonrails.org/v4.1/" data-turbo="false">Rails 4.1</a>,
-<a href="https://guides.rubyonrails.org/v4.0/" data-turbo="false">Rails 4.0</a>,
-<a href="https://guides.rubyonrails.org/v3.2/" data-turbo="false">Rails 3.2</a>,
-<a href="https://guides.rubyonrails.org/v3.1/" data-turbo="false">Rails 3.1</a>,
-<a href="https://guides.rubyonrails.org/v3.0/" data-turbo="false">Rails 3.0</a>, and
-<a href="https://guides.rubyonrails.org/v2.3/" data-turbo="false">Rails 2.3</a>.
-</p>