Resolve "Fix chart version"

General MR

Summary

Fix chart version from 9.0.X to the correct upstream, 1.21.2.

Relevant logs/screenshots

confluence-0              2/2     Running   0          147m
confluence-postgresql-0   2/2     Running   0          147m

Linked Issue

issue

Upgrade Notices

(Include any relevant notes about upgrades here or write "N/A" if there are none)

N/A

Closes #108 (closed)