Hugo warning about deprecated front matter key _build

[craigbox]

WARN  deprecated: The "_build" front matter key was deprecated in Hugo 0.145.0 and will be removed in a future release. Use "build" instead. See https://gohugo.io/content-management/build-options.

There are a few pages with this front matter

---
cascade:
  _build:
    render: always
    list: always
_build:
  render: never
  list: never
---

Removing the _ is probably the only fix required.