Correct typo in method name in tdm_loader

The method name "get_channels" has been corrected to "_get_channels" in the 'tdm_loader.py' file. The change was necessitated by the requirement for the method to be private, hence the underscore, as it's only meant for internal use, preventing unintended external access.

tdm_loader/tdm_loader.py

@@ -242,7 +242,7 @@ def channel_search(self, search_term):
             if channel_name:
                 group_uri = re.findall(r'id\("(.+?)"\)', channel.find("group").text)
                 group_id = channel_group_ids.get(group_uri[0])
-                channels = self.get_channels(group_id)
+                channels = self._get_channels(group_id)
 
                 channel_id = channels.get(channel.get("id"))