Bump graphql gem to 2.4.13

What does this MR do and why?

This MR bumps graphql gem to 2.4.13 (the version containing the necessary fix that made us vendor the gem in the first place) and removes vendored version.

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Verify that GraphQL API works as expected (e.g. by going to /-/graphql-explorer page to do some test queries)

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