Bump openskill from 1.6.0 to 3.1.0

Bumps [openskill](https://github.com/philihp/openskill.js) from 1.6.0 to 3.1.0.
- [Release notes](https://github.com/philihp/openskill.js/releases)
- [Commits](philihp/openskill.js@v1.6.0...v3.1.0)

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

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

package.json

@@ -26,7 +26,7 @@
     "express-session": "^1.17.3",
     "lodash": "^4.17.21",
     "object-hash": "^3.0.0",
-    "openskill": "^1.5.0",
+    "openskill": "^3.1.0",
     "passport": "^0.5.2",
     "passport-discord": "^0.1.4"
   },