Merge pull request optuna#5934 from HideakiImamura/mamu/update-readme-for-4.2.0

Update news section for 4.2.0 release

Author: c-bata

README.md

@@ -25,12 +25,12 @@ Optuna can dynamically construct the search spaces for the hyperparameters.
 
 ## :loudspeaker: News
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+* **Jan 20, 2025**: Optuna 4.2.0 and OptunaHub 0.2.0 are out! Try the newest Optuna and OptunaHub! Check out [the release note](https://github.com/optuna/optuna/releases/tag/v4.2.0) for details.
 * **Jan 16, 2025**: A new article [Overview of Python Free Threading (v3.13t) Support in Optuna](https://medium.com/optuna/overview-of-python-free-threading-v3-13t-support-in-optuna-ad9ab62a11ba) has been published.
 * **Nov 12, 2024**: We released Optuna 4.1 with new features, Python 3.13 support and much more! Check out [the release note](https://github.com/optuna/optuna/releases/tag/v4.1.0) for details.
 * **Nov 6, 2024**: A new article [AutoSampler: Automatic Selection of Optimization Algorithms in Optuna](https://medium.com/optuna/autosampler-automatic-selection-of-optimization-algorithms-in-optuna-1443875fd8f9) has been published.
 * **Oct 21, 2024**: We posted [an article](https://medium.com/optuna/an-introduction-to-moea-d-and-examples-of-multi-objective-optimization-comparisons-8630565a4e89) introducing [MOEA/D](https://hub.optuna.org/samplers/moead/) and an example comparison with other optimization methods.
 * **Oct 15, 2024**: We posted [an article](https://medium.com/optuna/introducing-a-new-terminator-early-termination-of-black-box-optimization-based-on-expected-9a660774fcdb) about `Terminator`, which is expanded in Optuna 4.0.
-* **Sep 18, 2024**: We posted [an article](https://medium.com/optuna/introducing-the-stabilized-journalstorage-in-optuna-4-0-from-mechanism-to-use-case-e320795ffb61) about `JournalStorage`, which is stabilized in Optuna 4.0.
 
 ## :fire: Key Features