Avoid specifying sidebar's icon fill color manually

With the default value of the icon_tag helper (fill-current)
it's already inheriting from the parent color.

admin/app/components/solidus_admin/sidebar/item/component.rb

@@ -20,7 +20,7 @@ def icon
     common_classes = "inline-block w-[1.125rem] h-[1.125rem] mr-[0.68rem] body-small"
 
     return tag.span(class: common_classes) unless @item.icon
-    icon_tag(@item.icon, class: "#{common_classes} align-text-bottom fill-black group-hover:fill-red-500 group-[.active]:fill-red-500")
+    icon_tag(@item.icon, class: "#{common_classes} align-text-bottom fill-current")
   end
 
   def path

admin/spec/spec_helper.rb

@@ -103,6 +103,7 @@
 
   config.include ViewComponent::TestHelpers, type: :component
   config.include ViewComponent::SystemTestHelpers, type: :component
+  config.include SolidusAdmin::ComponentHelpers, type: :component
 
   config.include Rails::Generators::Testing::Behaviour, type: :generator
   config.include FileUtils, type: :generator

admin/spec/support/solidus_admin/component_helpers.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module SolidusAdmin
+  module ComponentHelpers
+    # Mocks a component class with the given definition.
+    #
+    # @param definition [Proc] the component definition
+    # @example
+    #  mock_component do
+    #    def call
+    #      "Rendered"
+    #    end
+    #  end
+    def mock_component(&definition)
+      Class.new(SolidusAdmin::BaseComponent) do
+        # ViewComponent will complain if we don't fake a class name:
+        # @see https://github.com/ViewComponent/view_component/blob/5decd07842c48cbad82527daefa3fe9c65a4226a/lib/view_component/base.rb#L371
+        def self.name
+          "Foo"
+        end
+      end.tap { |klass| klass.class_eval(&definition) }
+    end
+  end
+end