Call GitHub graphql API directly from python

[widal001]

Summary

Update the analytics.integrations.github sub-package to call the GitHub GraphQL API directly from python instead of using the gh CLI as an intermediary.

Motivation

• The gh CLI uses a pinned version of go that has a CVE
• Simplifies the Dockerfile
• Removes a somewhat clunky sub-process call
• Enables us to add better error handling for GitHub API responses
• Enables us to mock the GitHub API for tests

Acceptance criteria

• [ ] The analytics.integrations.github sub-package calls the GitHub GraphQL API without using the gh CLI
• [ ] The make-graphql-query.sh has been replaced with a conceptually similar python function or method
• [ ] The gh CLI tool and jq are removed from the analytics/Dockerfile

[widal001]

Bumping this to sprint 1.4 since I won't have a chance to work on this until I'm back in office and it's not blocking anything.