fix(deps): override serialize-javascript to ^7.0.5 on mocha 11.x

Revert Mocha 12 beta; keep stable mocha ^11.7.5 and force patched
serialize-javascript (Dependabot #94 / GHSA-5c6j-r48x-rmvq) via npm overrides.

Co-authored-by: Daniel Imms <Tyriar@users.noreply.github.com>

package.json

@@ -99,7 +99,7 @@
     "express": "^5.2.1",
     "express-ws": "^5.0.2",
     "jsdom": "^29.1.1",
-    "mocha": "12.0.0-beta-10",
+    "mocha": "^11.7.5",
     "mustache": "^4.2.0",
     "node-pty": "^1.2.0-beta.9",
     "nyc": "^18.0.0",
@@ -115,5 +115,8 @@
     "webpack-cli": "^7.0.2",
     "ws": "^8.20.0",
     "xterm-benchmark": "^0.3.2"
+  },
+  "overrides": {
+    "serialize-javascript": "^7.0.5"
   }
 }