Bump @types/socket.io from 2.1.12 to 2.1.13 in /backend

Bumps [@types/socket.io](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/socket.io) from 2.1.12 to 2.1.13.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/socket.io)

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

Author: dependabot-preview[bot]

backend/package.json

@@ -14,7 +14,7 @@
   },
   "devDependencies": {
     "@types/lodash": "4.14.168",
-    "@types/socket.io": "^2.1.12",
+    "@types/socket.io": "^2.1.13",
     "@types/uuid": "^7.0.0",
     "ts-node-dev": "^1.0.0-pre.60",
     "ts-node": "^9.0.0",

backend/yarn.lock

@@ -26,10 +26,10 @@
   dependencies:
     "@types/node" "*"
 
-"@types/socket.io@^2.1.12":
-  version "2.1.12"
-  resolved "https://registry.yarnpkg.com/@types/socket.io/-/socket.io-2.1.12.tgz#91187f826a5dd2ed1113e935815bbaf9627e5cb0"
-  integrity sha512-oStc5VFkpb0AsjOxQUj9ztX5Iziatyla/rjZTYbFGoVrrKwd+JU2mtxk7iSl5RGYx9WunLo6UXW1fBzQok/ZyA==
+"@types/socket.io@^2.1.13":
+  version "2.1.13"
+  resolved "https://registry.yarnpkg.com/@types/socket.io/-/socket.io-2.1.13.tgz#b6d694234e99956c96ff99e197eda824b6f9dc48"
+  integrity sha512-JRgH3nCgsWel4OPANkhH8TelpXvacAJ9VeryjuqCDiaVDMpLysd6sbt0dr6Z15pqH3p2YpOT3T1C5vQ+O/7uyg==
   dependencies:
     "@types/engine.io" "*"
     "@types/node" "*"