updatechecker: raise app update notifications in the updatechecker job

the updatechecker runs even if auto-updates is disabled. doing notifications
in updatechecker ensures notifications are raised even when auto-update is disabled.

src/updater.js

@@ -274,10 +274,10 @@ async function autoUpdate(auditSource) {
             continue;
         }
 
+        if (!app.updateInfo) continue; // possible, if an update check happenned in parallel
+
         if (!app.updateInfo?.isAutoUpdatable) {
-            debug(`autoUpdate: ${app.fqdn} cannot be autoupdated. skipping`);
-            await notifications.pin(notifications.TYPE_MANUAL_APP_UPDATE_NEEDED, `${app.manifest.title} at ${app.fqdn} requires manual update to version ${appUpdateInfo.manifest.version}`,
-                `Changelog:\n${appUpdateInfo.manifest.changelog}\n`, { context: app.id });
+            debug(`autoUpdate: ${app.fqdn} requires manual update. skipping`);
             continue;
         }