tests: fix lint

lib/workers/pr/changelog/source-github.js

@@ -9,7 +9,6 @@ module.exports = {
 };
 
 async function getTags(endpoint, versionScheme, repository) {
-  const { isVersion } = versioning.get(versionScheme);
   let url = endpoint
     ? endpoint.replace(/\/?$/, '/')
     : 'https://api.github.com/';