Remove yaml Proc param parser test

I don't believe this test is exercising any explicit params_parser
behavior that the other two Proc tests aren't already doing.  Given
that we now know it's a bad idea to load user input via YAML.load,
somebody reading this test might get a dangerous idea about building
out a YAML params parser.
Merge pull request #9104 from bemurphy/remove_bad_idea_parser_test

Remove yaml Proc param parser test