fix: translate German MLS migration message [WPB-25947]

[Garzas]

https://wearezeta.atlassian.net/browse/WPB-25947

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PR Submission Checklist for internal contributors

• The PR Title

  • conforms to the style of semantic commits messages¹ supported in Wire's Github Workflow²
  • contains a reference JIRA issue number like SQPIT-764
  • answers the question: If merged, this PR will: ... ³

• The PR Description

  • is free of optional paragraphs and you have filled the relevant parts to the best of your ability

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What's new in this PR?

Cherry pick from #4967

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 48.93%. Comparing base (e16d539) to head (53abcfe).

Files with missing lines	Patch %	Lines
...e/conversations/messages/item/SystemMessageItem.kt	0.00%	1 Missing ⚠️

❌ Your patch check has failed because the patch coverage (0.00%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4968      +/-   ##
===========================================
- Coverage    48.93%   48.93%   -0.01%     
===========================================
  Files          643      643              
  Lines        23055    23056       +1     
  Branches      3521     3521              
===========================================
  Hits         11282    11282              
- Misses       10727    10728       +1     
  Partials      1046     1046              

Files with missing lines	Coverage Δ
...e/conversations/messages/item/SystemMessageItem.kt	0.00% <0.00%> (ø)

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud