chore: update React and related dependencies to latest versions

- Downgraded React and ReactDOM from version 19.1.0 to 18.3.1 for compatibility.
- Upgraded various Algolia packages, including `@algolia/abtesting`, `@algolia/client-abtesting`, and others, to version 5.49.0 to incorporate the latest features and fixes.
- Updated Docusaurus and related dependencies to version 3.9.2, ensuring alignment with the latest ecosystem changes.
- Adjusted lock files to reflect the updated dependency versions, enhancing overall project stability and performance.

Author: asdek