Bug 1997236 - Don't try to re-parse JSON in util.taskcluster.get_arti…

[Eijebong]

…fact

The previous code was only checking if the returned response from the taskcluster API was a dict to verify if it had been parsed or not. That works well until the JSON file we're getting contains something like a list in which case we skip the first condition, end up with a parsed response in if path.endswith(".json") and boom AttributeError: 'list' object has no attribute 'json'.

Since we already rely on the response type being requests.Request, I changed the logic to be:

• If we receive a dict, it might be either the parsed artifact content, or taskcluster giving us {"response": requests.Response} because it was unable to parse it.
• In the case where it's taskcluster's (detected by checking if "response" is in the dict and if it has the right type), peel it off, response is now the Response object and we can read from it.
• At this point we have 2 choices again, either response is a request.Response that we have to read, or anything else. If it is anything else then it's already been parsed by taskcluster so we just return it as is.
• Continue with the previous logic, try to parse the file based on the extension. I left the JSON case in there even though we should not be hitting it because it will raise on invalid JSON, which was the case previously too. Taskcluster masks JSON failures by returning the response object instead.