Arcanist ships with two linters intended to add copyright/license headers to files, ArcanistLicenseLinter (abstract base class) and ArcanistApacheLicenseLinter (specific to the Apache license). After T2035: Is there a legal reason to have license block in every single PHP file?, we no longer need these, and maintaining them is messy (see T2274: license linting doesn't allow for copyright years other than the current).

1. Delete these classes.
2. Grep for any use cases and delete them.
3. Run arc liberate.