File _service of Package python-libcst

<services>
  <service name="cargo_vendor" mode="manual">
     <param name="srcdir">libcst-*.tar.gz</param>
     <param name="cargotoml">native/Cargo.toml</param>
     <param name="update">true</param>
  </service>
  <service name="cargo_audit" mode="manual" />
</services>