fix: Accept tar and zip headers in contrib.utils.download requests (#1704)

* Add zip headers to the accepted content headers for contrib.utils.download
* Amends PR #1697

Co-authored-by: Graeme Watt <[email protected]>

Author: matthewfeickert

src/pyhf/contrib/utils.py

@@ -66,10 +66,8 @@ def download(archive_url, output_directory, force=False, compress=False):
         # The HEPData landing page for the resource file can check if the Accept
         # request HTTP header matches the content type of the resource file and
         # return the content directly if so.
-        # TODO: Figure out how to accept headers of both application/x-tar and
-        # application/zip.
         with requests.get(
-            archive_url, headers={"Accept": "application/x-tar"}
+            archive_url, headers={"Accept": "application/x-tar, application/zip"}
         ) as response:
             if response.status_code != 200:
                 raise exceptions.InvalidArchive(