Remove old tip

Author: weitzman

docs/generators.md

@@ -1,9 +1,5 @@
 # Overview
 
-!!! tip
-
-    Drush 11 and prior required generators to define a [drush.services.yml file](https://www.drush.org/11.x/dependency-injection/#services-files). This is no longer used with Drush 12+ generators. See [docs](dependency-injection.md) for injecting dependencies.
-
 Generators jump start your coding by building all the boring boilerplate code for you. After running the [generate command](commands/generate.md), you have a guide for where to insert your custom logic.
 
 Drush's generators reuse classes provided by the excellent [Drupal Code Generator](https://github.com/Chi-teck/drupal-code-generator) project. See its [Commands directory](https://github.com/Chi-teck/drupal-code-generator/tree/3.x/src/Command) for inspiration.