ytt - remove compose build context

config.yml

services:
  api:
    build:
      context: /path/to/my/repo/services/api
  client:
    build:
      context: /path/to/my/repo/services/client
    depends_on:
    - api
    - nginx
    - postgres
  foo:
    bar: baz

production.yml

#@ load("@ytt:overlay", "overlay")
#@overlay/match by=overlay.all
---
services:
  #@overlay/match by=overlay.all,expects="1+"
  _:
    #@overlay/match missing_ok=True
    #@overlay/remove
    build: