docs: remove duplicate reference

docs/src/auth.md

@@ -232,7 +232,7 @@ await page.goto('https://github.com/login')
 # Interact with login form
 await page.get_by_label("Username or email address").fill("username")
 await page.get_by_label("Password").fill("password")
-await page.page.get_by_role("button", name="Sign in").click()
+await page.get_by_role("button", name="Sign in").click()
 # Continue with the test
 ```