GraphQL: Upgrade graphql-ruby gem to 1.9.18

What does this MR do?

Since there are several breaking changes leading up to 1.10.x, upgrade first to 1.9.18

Related to #207278 (closed)

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Note to reviewers:

1. 99.9% of the changes are due to https://github.com/rmosolgo/graphql-ruby/blob/master/CHANGELOG.md#breaking-changes-2, which

   GraphQL::Schema::Resolver#initialize accepts a new keyword argument, field:. If you have overriden this method, you'll have to add that keyword to your argument list (and pass it along to super.) #2605

   It allows you to do lookaheads on a field during mutations. We don't need this at the moment, so it's safe to use field: nil for any resolver calls. Most of the files changes are the specs.

2. The autogenerated gitlab_schema.json is now sorted alphabetically (at least a portion of it), so that's why it has dramatically changed.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Closes #207278 (closed)