Updating fastly.toml loses local_server.pushpin section

**Version** ``` % npx fastly version Fastly CLI version v11.5.0 (617c3243) Built with go version go1.24.6 darwin/arm64 (2025-09-08) Viceroy version: viceroy 0.14.2 ``` **What happened** Invoking something that causes the Fastly CLI to update fastly.toml will wipe out the `local_server.pushpin` section.