Update gem httparty to >= 0.21.0 (Requires Ruby update)

[Janell-Huyck]

Note: Requires Require Ruby >= 2.3.0 (Current version 2.7.5)

We have httparty as part of kaltura v 0.1.1, which is pinned to that specific version, but kaltura only requires httparty (>= 0.7.8), so we should be able to update httparty.

For bundler-audit, error message:

Name: httparty
Version: 0.20.0
GHSA: GHSA-5pq7-52mg-hr42
Criticality: Medium
URL: GHSA-5pq7-52mg-hr42
Title: httparty has multipart/form-data request tampering vulnerability
Solution: upgrade to '>= 0.21.0'