build(deps): bump @google-cloud/firestore from 8.7.1 to 9.0.0

Bumps [@google-cloud/firestore](https://github.com/googleapis/google-cloud-node/tree/HEAD/handwritten/firestore) from 8.7.1 to 9.0.0.
- [Release notes](https://github.com/googleapis/google-cloud-node/releases)
- [Changelog](https://github.com/googleapis/google-cloud-node/blob/main/handwritten/firestore/CHANGELOG.md)
- [Commits](https://github.com/googleapis/google-cloud-node/commits/admin-v9.0.0/handwritten/firestore)

---
updated-dependencies:
- dependency-name: "@google-cloud/firestore"
  dependency-version: 9.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -215,7 +215,7 @@
     "jwks-rsa": "^4.0.1"
   },
   "optionalDependencies": {
-    "@google-cloud/firestore": "^8.7.1",
+    "@google-cloud/firestore": "^9.0.0",
     "@google-cloud/storage": "^7.22.0"
   },
   "devDependencies": {