Bump mongoose from 5.13.15 to 5.13.20

Bumps [mongoose](https://github.com/Automattic/mongoose) from 5.13.15 to 5.13.20.
- [Release notes](https://github.com/Automattic/mongoose/releases)
- [Changelog](https://github.com/Automattic/mongoose/blob/master/CHANGELOG.md)
- [Commits](Automattic/mongoose@5.13.15...5.13.20)

---
updated-dependencies:
- dependency-name: mongoose
  dependency-type: direct:production
...

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

package.json

@@ -38,7 +38,7 @@
     "fast-diff": "^1.2.0",
     "gif-encoder": "^0.7.2",
     "hot-shots": "^8.5.0",
-    "mongoose": "^5.13.15",
+    "mongoose": "^5.13.20",
     "node-canvas-with-twemoji": "^0.1.6",
     "open-graph-scraper": "^5.0.5",
     "rss-parser": "^3.7.2",