Where did the Bourne shell substitution string "{$pkg_scripts}" come from? It did not come from OpenBSD -release 6.0, nor from any of its packages, nor from any rcctl command string you could possibly have entered. The rc.conf(5) files have not been shell scripts for two years.
You did this damage to yourself once before, and you did it
only three weeks ago.
I have some simple advice to keep this from happening to you again.
Put the mouse down, and step away from the 3rd-party "how to" documents. 