Fix django-stubs-ext missing breaking a production setup (#2110)

Make django-stubs a non-dev-requirement. Just make StrOrPromise = Any if we're not typechecking. Use strict StrOrPromise with typeguard

evap/evaluation/models.py

@@ -30,10 +30,10 @@
 from django.utils.translation import gettext_lazy as _
 from django_fsm import FSMIntegerField, transition
 from django_fsm.signals import post_transition
-from django_stubs_ext import StrOrPromise
 
 from evap.evaluation.models_logging import FieldAction, LoggedModel
 from evap.evaluation.tools import (
+    StrOrPromise,
     clean_email,
     date_to_datetime,
     is_external_email,

evap/evaluation/tools.py

@@ -3,7 +3,7 @@
 from abc import ABC, abstractmethod
 from collections import defaultdict
 from collections.abc import Iterable, Mapping
-from typing import Any, Protocol, TypeVar
+from typing import TYPE_CHECKING, Any, Protocol, TypeVar
 from urllib.parse import quote
 
 import xlwt
@@ -16,7 +16,14 @@
 from django.utils.datastructures import MultiValueDict
 from django.utils.translation import get_language
 from django.views.generic import FormView
-from django_stubs_ext import StrOrPromise
+
+if TYPE_CHECKING:
+    from django_stubs_ext import StrOrPromise  # use proper definition with mypy
+else:
+    try:
+        from django_stubs_ext import StrOrPromise  # if installed, use proper definition for typeguard
+    except ImportError:
+        StrOrPromise = Any  # on production setups, type alias to Any
 
 M = TypeVar("M", bound=Model)
 T = TypeVar("T")

evap/staff/views.py

@@ -37,7 +37,6 @@
 from django.utils.translation import gettext_lazy, ngettext
 from django.views.decorators.http import require_POST
 from django.views.generic import CreateView, FormView, UpdateView
-from django_stubs_ext import StrOrPromise
 
 from evap.contributor.views import export_contributor_results
 from evap.evaluation.auth import manager_required, reviewer_required, staff_permission_required
@@ -65,6 +64,7 @@
     FormsetView,
     HttpResponseNoContent,
     SaveValidFormMixin,
+    StrOrPromise,
     get_object_from_dict_pk_entry_or_logged_40x,
     get_parameter_from_url_or_session,
     sort_formset,