Upgrade Heroku builder image to version 22
This change set upgrades the default
AUTO_DEVOPS_BUILD_IMAGE_CNB_BUILDER
from heroku/builder:20
to
heroku/builder:22
.
This is a breaking change!
Users are advised to upgrade their projects to be either compatible with
heroku/builder:22
or set the AUTO_DEVOPS_BUILD_IMAGE_CNB_BUILDER
environment variable to an image reference of their choosing.
More information about the Heroku images can be found in the Heroku cnb-builder-images project README at https://github.com/heroku/cnb-builder-images.
Closes #73 (closed)