chore: bump webonyx/graphql-php from 15.18.1 to 15.19.1 (#629)

Bumps [webonyx/graphql-php](https://github.com/webonyx/graphql-php) from 15.18.1 to 15.19.1.
- [Release notes](https://github.com/webonyx/graphql-php/releases)
- [Changelog](https://github.com/webonyx/graphql-php/blob/master/CHANGELOG.md)
- [Commits](webonyx/graphql-php@v15.18.1...v15.19.1)

---
updated-dependencies:
- dependency-name: webonyx/graphql-php
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Jared Hendrickson <github@jaredhendrickson.com>

Author: dependabot[bot]