Revert "fix: refactor changelog npm to work with new datasource"

This reverts commit 7bc9a2db.

lib/workers/pr/changelog/manager-npm.js

 const npmRegistry = require('../../../datasource/npm');
+const versioning = require('../../../versioning');
 
 module.exports = {
   getPackage,
 };
 
-async function getPackage({ depName, depType }) {
+async function getPackage({ versionScheme, depName, depType }) {
   if (depType === 'engines') {
     return null;
   }
+  const { sortVersions } = versioning(versionScheme);
   const dep = await npmRegistry.getDependency(depName);
   if (!dep) {
     return null;
   }
-  const versions = dep.releases.map(release => ({
-    version: release.version,
-    date: release.time,
-    gitHead: release.gitRef,
+  const releases = Object.keys(dep.versions);
+  releases.sort(sortVersions);
+  const versions = releases.map(release => ({
+    version: release,
+    date: dep.versions[release].time,
+    gitHead: dep.versions[release].gitHead,
   }));
   return {
     repositoryUrl: dep.repositoryUrl,