Clean up deprecated module removed in python 3.13 (#9004)

* Remove deprecated module removed in python 3.13

* Update validate to use helper function

* Add translation wrapper to error message

src/backend/InvenTree/part/serializers.py

@@ -1,6 +1,5 @@
 """DRF data serializers for Part app."""
 
-import imghdr
 import io
 import os
 from decimal import Decimal
@@ -298,9 +297,9 @@ class Meta:
 
     def validate_image(self, value):
         """Check that file is an image."""
-        validate = imghdr.what(value)
+        validate = InvenTree.helpers.TestIfImage(value)
         if not validate:
-            raise serializers.ValidationError('File is not an image')
+            raise serializers.ValidationError(_('File is not an image'))
         return value
 
     image = InvenTree.serializers.InvenTreeAttachmentSerializerField(required=True)