fix: Revert "fix(npm): deprecate only if deprecated === ‘this’"

This reverts commit 080d9451.

lib/datasource/npm.js

@@ -161,7 +161,7 @@ async function getDependency(name, retries = 5) {
       'renovate-config': latestVersion['renovate-config'],
     };
     Object.keys(dep.versions).forEach(version => {
-      if (dep.versions[version].deprecated === 'this') {
+      if (dep.versions[version].deprecated) {
         delete dep.versions[version];
       } else {
         // We don't use any of the version payload currently