Apply suggestion since part.blob changes type in the loop

Co-authored-by: Chatnoir Miki <[email protected]>

docxtpl/template.py

@@ -360,7 +360,7 @@ def render_footnotes(
         for section in self.docx.sections:
             for part in section.part.package.parts:
                 if part.content_type == 'application/vnd.openxmlformats-officedocument.wordprocessingml.footnotes+xml':
-                    xml = self.patch_xml(part.blob.decode('utf8'))
+                    xml = self.patch_xml(part.blob.decode('utf-8') if type(part.blob) is bytes else part.blob)
                     xml = self.render_xml_part(xml, part, context, jinja_env)
                     part._blob = xml