Bump @testing-library/react from 14.3.0 to 15.0.0 (#2770)

Bumps [@testing-library/react](https://github.com/testing-library/react-testing-library) from 14.3.0 to 15.0.0.
- [Release notes](https://github.com/testing-library/react-testing-library/releases)
- [Changelog](https://github.com/testing-library/react-testing-library/blob/main/CHANGELOG.md)
- [Commits](testing-library/react-testing-library@v14.3.0...v15.0.0)

---
updated-dependencies:
- dependency-name: "@testing-library/react"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Martijn Verburg <martijnverburg@gmail.com>

package.json

@@ -70,7 +70,7 @@
  },
  "devDependencies": {
  "@testing-library/jest-dom": "^6.4.2",
- "@testing-library/react": "^14.3.0",
+ "@testing-library/react": "^15.0.0",
  "@testing-library/user-event": "^14.5.1",
  "@types/gatsbyjs__reach-router": "^2.0.4",
  "@types/prismjs": "^1.26.3",