refactor(batch): improve type annotation for event parameter

[maxrabin]

Issue number: closes #7923

Summary

Changes

Changed the event parameter type annotation from dict to dict[str, Any] in both process_partial_response and async_process_partial_response functions in aws_lambda_powertools/utilities/batch/decorators.py.

User experience

Before: When using strict type checkers like pyright, users would see type errors:

error: Type of "process_partial_response" is partially unknown
  Type of "process_partial_response" is "(event: dict[Unknown, Unknown], ...)" (reportUnknownVariableType)

After: Type checkers correctly infer event: dict[str, Any], eliminating the type error and providing better IDE support and type safety.

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[boring-cyborg]

Thanks a lot for your first contribution! Please check out our contributing guidelines and don't hesitate to ask whatever you need.
In the meantime, check out the #python channel on our Powertools for AWS Lambda Discord: Invite link

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.72%. Comparing base (4171897) to head (0a0dead).
⚠️ Report is 2 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #7924   +/-   ##
========================================
  Coverage    96.72%   96.72%           
========================================
  Files          275      275           
  Lines        13214    13214           
  Branches      1006     1006           
========================================
  Hits         12781    12781           
  Misses         325      325           
  Partials       108      108           

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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

[leandrodamascena]

Thanks a lot for improving this @maxrabin! APPROVED!

[boring-cyborg]

Awesome work, congrats on your first merged pull request and thank you for helping improve everyone's experience!