refactor: bump @graphql-tools/merge from 9.0.18 to 9.0.19

Bumps [@graphql-tools/merge](https://github.com/ardatan/graphql-tools/tree/HEAD/packages/merge) from 9.0.18 to 9.0.19.
- [Release notes](https://github.com/ardatan/graphql-tools/releases)
- [Changelog](https://github.com/ardatan/graphql-tools/blob/master/packages/merge/CHANGELOG.md)
- [Commits](https://github.com/ardatan/graphql-tools/commits/@graphql-tools/[email protected]/packages/merge)

---
updated-dependencies:
- dependency-name: "@graphql-tools/merge"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -22,7 +22,7 @@
   "dependencies": {
     "@apollo/server": "4.11.3",
     "@babel/eslint-parser": "7.26.5",
-    "@graphql-tools/merge": "9.0.18",
+    "@graphql-tools/merge": "9.0.19",
     "@graphql-tools/schema": "10.0.16",
     "@graphql-tools/utils": "10.6.3",
     "@parse/fs-files-adapter": "3.0.0",