[dendrite] 0.9.1 -> 0.9.3

[wrmilling]

Description of the change

Security and bug fixes to the dendrite home server. Details can be found on the dendrite releases page.

Benefits

Increased functionality and security.

Possible drawbacks

N/A

Applicable issues

N/A

Additional information

N/A

Checklist

• [X] Title of the PR starts with chart name (e.g. [home-assistant])
• [X] Chart version bumped in Chart.yaml according to semver.
• [X] Chart artifacthub.io/changes changelog annotation has been updated in Chart.yaml. See Artifact Hub documentation for more info.
• [X] Variables have been documented in the values.yaml file.

[wrmilling]

Closing in favor of #1743