Remove more python2 stuff

InvenTree/report/admin.py

@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.contrib import admin
 
 from .models import ReportSnippet, ReportAsset

InvenTree/report/api.py

@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
 
 from django.utils.translation import gettext_lazy as _
 from django.urls import include, path, re_path

InvenTree/report/serializers.py

@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
 
 from InvenTree.serializers import InvenTreeModelSerializer
 from InvenTree.serializers import InvenTreeAttachmentSerializerField

InvenTree/report/tests.py

@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
 
 import os
 import shutil