Upgrade to Faraday v2 for omniauth_openid_connect and openid_connect gems

omniauth_openid_connect v0.7 requires openid_connect v2, which requires Faraday v2. However, we can't upgrade to those supported versions because we are blocked on upgrading to Faraday v2 due to a number of gems:

1. danger
2. ms_rest and ms_rest_azure ➡ gitlab-org/ruby/gems/gitlab-fog-azure-rm#3 (closed)