stylelint selector-no-utility has a runtime primer-utilities dependency

[shawnbot]

We've got issues updating Primer in github/github with also having to update the version of stylelint-config-primer because the common version of primer-utilities must match exactly in order for that package to be "hoisted" to the top-level node_modules directory. (In other words, if you don't update stylelint-config-primer when you're updating primer, you end up with separate versions of primer-utilities in each of the dependent package's own node_modules directories.)

One way to do this is to make primer-utilities a dev dependency and "bake" the utility classes into the library at build/publish time.

Another is to loosen the primer-utilities version specifier so that npm can hoist the specific version from primer.

@emplums @jonrohan, any thoughts, preferences?

[shawnbot]

Fixed in #597!