中国区需要转发网络请求。
settings.json 里这么配置，重启vscode生效

    "http.proxy": "http://<ip>:<port>",
    "remote.extensionKind": {
        "Gitihub.copilot": ["ui"],
        "Gitihub.copilot-chat": ["ui"],
        "Gitihub.copilot-labs": ["ui"],
        "Gitihub.copilot-chat-labs": ["ui"],
        "pub.name": [
            "ui"
        ]
    }