Remove coccinelle checks from check-local

Right now, check-local invokes check_cocci_parse.sh, which means that if you have coccinelle installed, it will warn about any files that coccinelle can't parse.

This is causing me trouble, as there are version differences among coccinelle installations. I think it makes more sense for us to have check_cocci_parse.sh be an occasionally invoked thing that we run before we're about to do a cocci-based refactoring.

Alternatively, we can do like practracker in #40019 (closed), and have an environment variable that enables coccinelle checking, and have it off by default.