Update plugin com.diffplug.spotless to v8.4.0

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
com.diffplug.spotless	8.3.0 → 8.4.0

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Configuration

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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

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (c53c822) to head (de5122d).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##                main      #467   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
  Complexity       426       426           
===========================================
  Files             76        76           
  Lines           1376      1376           
  Branches         210       210           
===========================================
  Hits            1376      1376           

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