fix(next): disables active nav item (#11434)

When visiting a collection's list view, the nav item corresponding to
that collection correctly appears in an active state, but is still
rendered as an anchor tag. This makes it possible to reload the current
page by simply clicking the link, which is a problem because this
performs an unnecessary server roundtrip. This is especially apparent
when search params exist in the current URL, as the href on the link
does not.

Unrelated: also cleans up leftover code that was missed in this PR:
#11155

test/helpers.ts

@@ -255,18 +255,6 @@ export async function saveDocAndAssert(
   }
 }
 
-export async function openNav(page: Page): Promise<void> {
-  // check to see if the nav is already open and if not, open it
-  // use the `--nav-open` modifier class to check if the nav is open
-  // this will prevent clicking nav links that are bleeding off the screen
-  if (await page.locator('.template-default.template-default--nav-open').isVisible()) {
-    return
-  }
-  // playwright: get first element with .nav-toggler which is VISIBLE (not hidden), could be 2 elements with .nav-toggler on mobile and desktop but only one is visible
-  await page.locator('.nav-toggler >> visible=true').click()
-  await expect(page.locator('.template-default.template-default--nav-open')).toBeVisible()
-}
-
 export async function openDocDrawer(page: Page, selector: string): Promise<void> {
   await wait(500) // wait for parent form state to initialize
   await page.locator(selector).click()