chore(deps): update helm chart common to v6.8.4 (#792)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

charts/stable/owncast/Chart.yaml

@@ -3,7 +3,7 @@ appVersion: auto
 dependencies:
 - name: common
   repository: https://truecharts.org
-  version: 6.8.3
+  version: 6.8.4
 description: Take control over your live stream video by running it yourself. Streaming
   + chat out of the box.
 home: https://github.com/truechartsapps/tree/master/charts/incubator/owncast
@@ -22,4 +22,4 @@ name: owncast
 sources:
 - https://owncast.online/
 - https://github.com/owncast/owncast
-version: 1.4.14
+version: 1.4.15