Intelephense (PHP language server) has a dependency on `protobufjs`
which invokes `node` in the `postinstall` script and if the user did not
have a system Node runtime installed that would fail. Have this use our
downloaded installation too

Fixes
https://linear.app/zed-industries/issue/Z-2687/php-language-server-failed

Release Notes:
- Fixed PHP language server installation on systems without a system
Node installation.