chore(deps): update container image ich777/thunderbird to latest@8d40a6d by renovate (#24919)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| ich777/thunderbird | digest | `965218e` -> `8d40a6d` |

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<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzOC4yMy4yIiwidXBkYXRlZEluVmVyIjoiMzguMjMuMiIsInRhcmdldEJyYW5jaCI6Im1hc3RlciIsImxhYmVscyI6WyJhdXRvbWVyZ2UiLCJ1cGRhdGUvZG9ja2VyL2dlbmVyYWwvbm9uLW1ham9yIl19-->

charts/stable/thunderbird/Chart.yaml

@@ -33,4 +33,4 @@ sources:
   - https://hub.docker.com/r/ich777/thunderbird
   - https://www.thunderbird.net/
 type: application
-version: 7.1.4
+version: 7.1.5

charts/stable/thunderbird/values.yaml

@@ -1,7 +1,7 @@
 image:
   pullPolicy: IfNotPresent
   repository: ich777/thunderbird
-  tag: latest@sha256:965218eb75b9a3e6d47840d150ee2d06bbce93d843905166d120be41bbc6c1ee
+  tag: latest@sha256:8d40a6d251508f53b606ee411a9980810cb9674eb9b5f12ff9852ed9a5647eca
 persistence:
   data:
     enabled: true