Feature/upgrade optuna 4.2.1

[dahlem]

Upgrade hydra_optuna_sweeper to Optuna 4.2.1

Summary

This PR upgrades the hydra_optuna_sweeper plugin to use Optuna 4.2.1 (from 3.0.0) and updates the code to comply with the latest
Optuna APIs, replacing deprecated distribution classes and methods.

Changes

• Replace deprecated distribution classes with modern equivalents:
  • DiscreteUniformDistribution → FloatDistribution with step parameter
  • IntUniformDistribution, IntLogUniformDistribution → IntDistribution
  • UniformDistribution, LogUniformDistribution → FloatDistribution
• Update Trial API usage to public methods instead of internal ones
• Update sampler configurations to remove deprecated parameters
• Update tests to reflect the new distribution classes
• Add news entry (enable python3.10 CI for Windows #2444)

Test Plan

• Unit tests for distribution classes and API pass
• Example applications run successfully
• Manual testing with different samplers and storage options

Backward Compatibility

This change maintains backward compatibility with existing configurations.

[charleswilmot]

I need this!