Enable exiting composer when a patch failes to apply

[b-sharpe]

Currently patches just get skipped if they fail to apply. This is potentially hazardous to a core update (or others) in which a patch provided by OpenY may no longer apply but is allowed to pass installation and update.

I will put in a PR when I get a minute, but wanted this documented so I don't forget.

just need to add
"composer-exit-on-patch-failure": true,

This technically should apply to the main package as well for development, but is more important on the project for now.