Remove deprecated lints from `ArcanistXHPASTLinter`

Summary: After D9576, `LINT_PHP_53_FEATURES` and `LINT_PHP_54_FEATURES` are deprecated. They have been replaced by `LINT_PHP_COMPATIBILITY`.

Test Plan: `arc unit`

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9657