Pre-release manifest.json update.

[jakubnowicki]

Have you read the Contributing Guidelines?

Issue #

Description

Clear and concise description of what changed and why.
If necessary, include screenshots and/or a step-by-step guide on how to test the changes.

Definition of Done

• The change is thoroughly documented.
• The CI passes (R CMD check, linter, unit tests, spelling).
• Any generated files have been updated (e.g. .Rd files with roxygen2::roxygenise())