chore(deps): update container image ich777/thunderbird to latest@c840084 by renovate (#26577)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| ich777/thunderbird | digest | `da4cb14` -> `c840084` |

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charts/stable/thunderbird/Chart.yaml

@@ -33,4 +33,4 @@ sources:
   - https://hub.docker.com/r/ich777/thunderbird
   - https://www.thunderbird.net/
 type: application
-version: 7.1.10
+version: 7.1.11

charts/stable/thunderbird/values.yaml

@@ -1,7 +1,7 @@
 image:
   pullPolicy: IfNotPresent
   repository: ich777/thunderbird
-  tag: latest@sha256:da4cb1472346ad88f13ddac92ff12975a2068dc8987192c22fe13ae1c6c32ecf
+  tag: latest@sha256:c84008480334c29047bd9bfbaeef1b1eb0bf33abb16b5015b5a7d87d0c73cade
 persistence:
   data:
     enabled: true