Fixes: #18184 - Gracefully handle unavailable internet connection on RSS feed dashboard widget if ISOLATED_DEPLOYMENT is set (#18186)

* Suppress adding the RSS feed widget to the dashboard if ISOLATED_DEPLOYMENT is set

* Add config option on RSSFeedWidget to specify requires_internet and to display a more appropriate error if ISOLATED_DEPLOYMENT is set

* Remove skipping behavior from utils.py

* Add required=False

netbox/extras/constants.py

@@ -79,6 +79,7 @@ DEFAULT_DASHBOARD = [
             'feed_url': 'http://netbox.dev/rss/',
             'max_entries': 10,
             'cache_timeout': 14400,
+            'requires_internet': True,
         }
     },
     {