Don't explicitly implement ArcanistPuppetLintLinter::supportsReadDataFromStdin

Summary: false is the default return value for this method.

Test Plan: arc unit

Reviewers: epriestley, Blessed Reviewers

Reviewed By: epriestley, Blessed Reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11314