fix: fix skeleton not appearing on feature toggle list (#6093)

The `FeatureToggleListTable` is nested directly within `PageContent`.
`PageContent` was cause for removing the skeleton from the table.
However, this is unnecessary because the table has its own loader that
manages the skeletons. Therefore, `PageContent` does not require a
loader.

frontend/src/component/feature/FeatureToggleList/FeatureToggleListTable.tsx

@@ -312,6 +312,7 @@ export const FeatureToggleListTable: VFC = () => {
 
     return (
         <PageContent
+            disableLoading={true}
             bodyClass='no-padding'
             header={
                 <PageHeader