Fix django-pipeline tests

Change tests after undocumented change in Django.render_js
Complet issue: https://code.djangoproject.com/ticket/31892

HISTORY.rst

@@ -11,6 +11,8 @@ History
   of the current version to prevent error while importing. Thank to @vmsp
 * Context in django.template.base is removed from Django and
   not used anymore in django-pipeline.
+* Fixing widgets tests of django-pipeline due to Media.render_js change in 
+  Django. More information in Django ticket #31892
 
 2.0.4
 ======

pipeline/storage.py

@@ -2,9 +2,9 @@
 
 from io import BytesIO
 
-import django
+from django import get_version as django_version
 
-_CACHED_STATIC_FILES_STORAGE_AVAILABLE = django.VERSION[0] <= 3 and django.VERSION[1] < 1
+_CACHED_STATIC_FILES_STORAGE_AVAILABLE = django_version() < '3.1'
 
 if _CACHED_STATIC_FILES_STORAGE_AVAILABLE:
     from django.contrib.staticfiles.storage import CachedStaticFilesStorage

tests/tests/test_forms.py

@@ -1,3 +1,4 @@
+from django import get_version as django_version
 from django.forms import Media
 from django.test import TestCase
 
@@ -147,6 +148,7 @@ class MyMedia(PipelineFormMedia):
             js = ('extra1.js', 'extra2.js')
 
         media = Media(MyMedia)
+        script_tag = '<script type="text/javascript" src="%s"></script>' if django_version() < '3.1' else '<script src="%s"></script>'
 
         self.assertEqual(
             MyMedia.js,
@@ -160,7 +162,7 @@ class MyMedia(PipelineFormMedia):
         self.assertEqual(
             media.render_js(),
             [
-                '<script type="text/javascript" src="%s"></script>' % path
+                script_tag % path
                 for path in (
                     '/static/extra1.js',
                     '/static/extra2.js',
@@ -177,6 +179,7 @@ class MyMedia(PipelineFormMedia):
             js = ('extra1.js', 'extra2.js')
 
         media = Media(MyMedia)
+        script_tag = '<script type="text/javascript" src="%s"></script>' if django_version() < '3.1' else '<script src="%s"></script>'
 
         self.assertEqual(
             MyMedia.js,
@@ -191,7 +194,7 @@ class MyMedia(PipelineFormMedia):
         self.assertEqual(
             media.render_js(),
             [
-                '<script type="text/javascript" src="%s"></script>' % path
+                script_tag % path
                 for path in (
                     '/static/extra1.js',
                     '/static/extra2.js',