Add codenarc to CI for groovy files

[nrmancuso]

Now that we are keeping groovy files in the main Checkstyle repo(after #11731), we should have a static analysis tool to make sure that we keep the same quality in Groovy code that we do for Java.

Let's add codenarc to CI execution now that we are adding groovy to main repo. Take a look at contribution to see how it is done there: https://github.com/checkstyle/contribution/blob/master/checkstyle-tester/codenarc.sh

Originally posted by @nick-mancuso in #11731 (comment)

[nrmancuso]

Closed via #11739