Fix: Remove upload_pdf view from urls.py

backend/api/urls.py

@@ -1,14 +1,12 @@
 from django.urls import path
 
 from users.views import login, register_user
-from documents.views import upload_pdf
 from flashcards.views import generate_mock_flashcard
 from documents.views import create_flashcards
 
 urlpatterns = [
     path("create-user/", register_user, name="create-user"),
     path("login/", login, name="login"),
-    path("upload/", upload_pdf, name="upload"),
     path("generate-mock-flashcard/", generate_mock_flashcard, name="generate-mock-flashcards"),
     path("create-flashcards/", create_flashcards, name="create-flashcards"),
 ]