Remove mentions about `javascripts` option from the guide about generators [ci skip]

This option is unused since #33079.

Follow up #34277

guides/source/generators.md

@@ -219,7 +219,7 @@ If we want to avoid generating the default `app/assets/stylesheets/scaffolds.scs
   end
 ```
 
-The next customization on the workflow will be to stop generating stylesheet, JavaScript, and test fixture files for scaffolds altogether. We can achieve that by changing our configuration to the following:
+The next customization on the workflow will be to stop generating stylesheet and test fixture files for scaffolds altogether. We can achieve that by changing our configuration to the following:
 
 ```ruby
 config.generators do |g|
@@ -227,7 +227,6 @@ config.generators do |g|
   g.template_engine :erb
   g.test_framework  :test_unit, fixture: false
   g.stylesheets     false
-  g.javascripts     false
 end
 ```
 
@@ -285,7 +284,6 @@ config.generators do |g|
   g.template_engine :erb
   g.test_framework  :test_unit, fixture: false
   g.stylesheets     false
-  g.javascripts     false
   g.helper          :my_helper
 end
 ```
@@ -350,7 +348,6 @@ config.generators do |g|
   g.template_engine :erb
   g.test_framework  :test_unit, fixture: false
   g.stylesheets     false
-  g.javascripts     false
 end
 ```
 
@@ -385,7 +382,6 @@ config.generators do |g|
   g.template_engine :erb
   g.test_framework  :shoulda, fixture: false
   g.stylesheets     false
-  g.javascripts     false
 
   # Add a fallback!
   g.fallbacks[:shoulda] = :test_unit