Update app version to newest mastodon version

Author: timetinytim

Chart.yaml

@@ -20,7 +20,7 @@ version: 4.1.1
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
 # follow Semantic Versioning. They should reflect the version the application is using.
-appVersion: v4.2.5
+appVersion: v4.2.7
 
 dependencies:
   - name: elasticsearch