fix: babel vulnerable to arbitrary code execution when compiling specifically crafted malicious code (#15840)

Resolves [Dependabot Alert
95](https://github.com/twentyhq/twenty/security/dependabot/95) - babel
vulnerable to arbitrary code execution when compiling specifically
crafted malicious code.

These were the few options we had for a direct drop-in replacement.
- [x-var](https://www.npmjs.com/package/x-var?activeTab=readme)
- [cross-let](https://www.npmjs.com/package/cross-let)
- [cross-var-no-babel](https://www.npmjs.com/package/cross-var-no-babel)

x-var has the most weekly downloads among the three and it is also the
most actively maintained fork of the original cross-var package that
introduced the vulnerability. There is no syntax difference per the
documentation, but I do not have a windows machine to test.

`cross-var-no-babel` offers the most minimal changes, but is also
abandoned without a public-facing repo.

package.json

@@ -149,7 +149,6 @@
     "@yarnpkg/types": "^4.0.0",
     "chromatic": "^6.18.0",
     "concurrently": "^8.2.2",
-    "cross-var": "^1.1.0",
     "danger": "^13.0.4",
     "dotenv-cli": "^7.4.4",
     "esbuild": "^0.25.10",