Fix Copilot Cookbook navigation bar duplicate entries (#57198)

Author: heiskr

content/copilot/tutorials/copilot-chat-cookbook/index.md

@@ -12,7 +12,7 @@ topics:
 layout: category-landing
 sidebarLink:
   text: All prompts
-  href: /copilot/copilot-chat-cookbook
+  href: /copilot/tutorials/copilot-chat-cookbook
 spotlight:
   - article: /testing-code/generate-unit-tests
     image: /assets/images/copilot-landing/generating_unit_tests.png

src/landings/components/SidebarProduct.tsx

@@ -102,7 +102,7 @@ function NavListItem({ childPage }: { childPage: ProductTreeNode }) {
               {childPage.sidebarLink.text}
             </NavList.Item>
           )}
-          {specialCategory && (
+          {specialCategory && !childPage.sidebarLink && (
             <NavList.Item href={childPage.href} as={Link} aria-current={isActive ? 'page' : false}>
               {childPage.title}
             </NavList.Item>