DEV: Clear local stylesheet caches when working on WCAG color schemes (#16600)

This isn't a complete fix, it doesn't enable live reloading of color
definition stylesheets. But at least now when working on WCAG overrides
the developer won't need to restart the server to see changes.

lib/stylesheet/watcher.rb

@@ -70,7 +70,7 @@ module Stylesheet
               end
 
               target = nil
-              target_match = long.match(/admin|desktop|mobile|publish|wizard/)
+              target_match = long.match(/admin|desktop|mobile|publish|wizard|wcag|color_definitions/)
               if target_match&.length
                 target = target_match[0]
               end
@@ -93,6 +93,11 @@ module Stylesheet
     end
 
     def core_assets_refresh(target)
+      if target.match(/wcag|color_definitions/)
+        Stylesheet::Manager.clear_color_scheme_cache!
+        return
+      end
+
       targets = target ? [target] : ["desktop", "mobile", "admin"]
       Stylesheet::Manager.clear_core_cache!(targets)
       message = targets.map! do |name|