docs: remove two

There are only two install method in this page.

Author: kenjis

user_guide_src/source/installation/installing_composer.rst

@@ -128,7 +128,7 @@ In your project root::
 
     > composer require codeigniter4/framework
 
-As with the earlier two composer install methods, you can omit installing
+As with the earlier composer install method, you can omit installing
 phpunit and its dependencies by adding the ``--no-dev`` argument to the ``composer require`` command.
 
 Setting Up