Replace core/scripts/generate-proxy.sh mentions with actual command

Seems pretty straight forward. Searched for core/scripts/generate-proxy.sh and all instances updated.

We should be able to deprecate this command relatively soon once we're using service closures everywhere, but in the meantime should point to the right command.

catch → closed merge request !12417

Fixing d.o eating catch's credits. Also @smustgrave's review there is actually creditable, so adding credit for that too.

Automatically closed - issue fixed for 2 weeks with no activity.