Removed PIL compatability layer per deprecation timeline.

refs #19934.

django/db/models/fields/files.py

@@ -4,7 +4,6 @@ import os
 from django import forms
 from django.db.models.fields import Field
 from django.core import checks
-from django.core.exceptions import ImproperlyConfigured
 from django.core.files.base import File
 from django.core.files.storage import default_storage
 from django.core.files.images import ImageFile
@@ -386,8 +385,8 @@ class ImageField(FileField):
 
     def _check_image_library_installed(self):
         try:
-            from django.utils.image import Image  # NOQA
-        except ImproperlyConfigured:
+            from PIL import Image  # NOQA
+        except ImportError:
             return [
                 checks.Error(
                     'Cannot use ImageField because Pillow is not installed.',