GitHub Copilot for Xcode Fails in Enterprise Environments with MITM Proxy

**Describe the bug**
In our enterprise environment, HTTPS traffic is intercepted and inspected using a MITM proxy, requiring the installation of a custom root certificate on all machines. While Node.js allows configuring the trust for a custom root certificate using environment variables such as `NODE_EXTRA_CA_CERTS=/path/to/certificate.pem`, GitHub Copilot for Xcode lacks an equivalent option. This results in the error: `unable to get local issuer certificate`.

**Versions**
- Copilot for Xcode: 0.29.0
- Xcode: 16.2 (likely not relevant)
- macOS: 14.7.2 (likely not relevant)

**Steps to reproduce**
1. Set up GitHub Copilot for Xcode in an enterprise network using a MITM proxy.
2. Attempt to use GitHub Copilot for Xcode on a project.
3. Observe that GitHub Copilot for Xcode fails to make suggestions due to certificate validation issues.

**Screenshots**
N/A

**Logs**
```plaintext
[2025-01-07T07:12:51.736Z] [info] [GitHubCopilot] [83702] window/logMessage: {
"message" : "[contentExclusion] Fetching content exclusion policies {\n params: {\n repos: 'git@path.to.github.enterprise:org\/repo.git',\n scope: 'repo'\n }\n}",
"type" : 4
}
[2025-01-07T07:12:51.788Z] [info] [GitHubCopilot] [83702] window/logMessage: {
"message" : "[contentExclusion] FetchError: unable to get local issuer certificate\n at fetch (\/snapshot\/copilot-client\/node_modules\/@adobe\/helix-fetch\/src\/fetch\/index.js:99:11)\n at processTicksAndRejections (node:internal\/process\/task_queues:95:5)\n at cachingFetch (\/snapshot\/copilot-client\/node_modules\/@adobe\/helix-fetch\/src\/fetch\/index.js:288:16)\n at zge.fetch (\/snapshot\/copilot-client\/lib\/src\/network\/helix.ts:93:22)\n at \/snapshot\/copilot-client\/lib\/src\/contentExclusion\/contentExclusions.ts:228:24 {\n type: 'system',\n _name: 'FetchError',\n code: 'UNABLE_TO_GET_ISSUER_CERT_LOCALLY',\n errno: undefined,\n erroredSysCall: undefined\n} Error evaluating policy for ",
"type" : 1
}
```

**Additional context**
In other environments, such as VSCode or IntelliJ IDEA, I can use GitHub Copilot by configuring the custom root certificate. This highlights that the issue is specific to GitHub Copilot for Xcode.