Bump flat-cache from 4.0.1 to 6.1.3

Bumps [flat-cache](https://github.com/jaredwray/cacheable/tree/HEAD/packages/flat-cache) from 4.0.1 to 6.1.3.
- [Release notes](https://github.com/jaredwray/cacheable/releases)
- [Commits](https://github.com/jaredwray/cacheable/commits/HEAD/packages/flat-cache)

---
updated-dependencies:
- dependency-name: flat-cache
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

package.json

@@ -42,7 +42,7 @@
     "discord.js": "^13.16.0",
     "fast-json-stable-stringify": "^2.1.0",
     "fastify": "^4.25.2",
-    "flat-cache": "^4.0.0",
+    "flat-cache": "^6.1.3",
     "form-data": "^4.0.0",
     "geo-tz": "^8.0.0",
     "handlebars": "^4.7.7",