requirements: upgrade MozPhab to 2.8.3 (Bug 2020729) r=zeid

Also take other minor package updates from `make upgrade-requirements`.

Pull request: #965

Author: cgsheeh

pyproject.toml

@@ -22,7 +22,7 @@ dependencies = [
     "jinja2",
     "kombu",
     "mots",
-    "MozPhab==2.8.0",
+    "MozPhab==2.8.3",
     "mozilla_django_oidc",
     "networkx",
     "psycopg2-binary",