remove require_* statements from application.css

With Propshaft as the default asset pipeline in Rails 8, the require_tree and require_self clauses in application.css are no longer necessary, as they were specific to Sprockets. Additionally, the comment has been updated to clarify that CSS precedence now follows standard cascading order without automatic prioritization by the asset pipeline.

Author: jeduardo824

railties/CHANGELOG.md

@@ -1,3 +1,9 @@
+*   Remove `require_*` statements from application.css to align with the transition from Sprockets to Propshaft.
+
+    With Propshaft as the default asset pipeline in Rails 8, the require_tree and require_self clauses in application.css are no longer necessary, as they were specific to Sprockets. Additionally, the comment has been updated to clarify that CSS precedence now follows standard cascading order without automatic prioritization by the asset pipeline.
+
+    *Eduardo Alencar*
+
 *   Do not include redis by default in generated Dev Containers.
 
     Now that applications use the Solid Queue and Solid Cache gems by default, we do not need to include redis

railties/lib/rails/generators/rails/app/templates/app/assets/stylesheets/application.css.tt

@@ -1,15 +1,10 @@
 /*
- * This is a manifest file that'll be compiled into application.css, which will include all the files
- * listed below.
+ * This is a manifest file that'll be compiled into application.css.
  *
- * Any CSS (and SCSS, if configured) file within this directory, lib/assets/stylesheets, or any plugin's
- * vendor/assets/stylesheets directory can be referenced here using a relative path.
+ * With Propshaft, assets are served efficiently without preprocessing steps. You can still include
+ * application-wide styles in this file, but keep in mind that CSS precedence will follow the standard
+ * cascading order, meaning styles declared later in the document or manifest will override earlier ones,
+ * depending on specificity.
  *
- * You're free to add application-wide styles to this file and they'll appear at the bottom of the
- * compiled file so the styles you add here take precedence over styles defined in any other CSS
- * files in this directory. Styles in this file should be added after the last require_* statement.
- * It is generally better to create a new file per style scope.
- *
- *= require_tree .
- *= require_self
+ * Consider organizing styles into separate files for maintainability.
  */