fix: prevents duplicate active nav indicators (#7943)

Author: JarrodMFlesch

packages/next/src/elements/Nav/index.client.tsx

@@ -88,7 +88,8 @@ export const DefaultNavClient: React.FC = () => {
                 LinkWithDefault) as typeof LinkWithDefault.default
 
               const LinkElement = Link || 'a'
-              const activeCollection = pathname.startsWith(href)
+              const activeCollection =
+                pathname.startsWith(href) && ['/', undefined].includes(pathname[href.length])
 
               return (
                 <LinkElement