build(deps): bump mongoose from 8.6.3 to 8.7.0 in /apps/OpenSignServer

Bumps [mongoose](https://github.com/Automattic/mongoose) from 8.6.3 to 8.7.0.
- [Release notes](https://github.com/Automattic/mongoose/releases)
- [Changelog](https://github.com/Automattic/mongoose/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Automattic/mongoose/compare/8.6.3...8.7.0)

---
updated-dependencies:
- dependency-name: mongoose
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

apps/OpenSignServer/package.json

@@ -34,7 +34,7 @@
     "googleapis": "^144.0.0",
     "jsonschema": "^1.4.1",
     "mailgun.js": "^10.2.3",
-    "mongoose": "^8.6.3",
+    "mongoose": "^8.7.0",
     "multer": "^1.4.5-lts.1",
     "multer-s3": "^3.0.1",
     "node-forge": "^1.3.1",