Allow empty array as task body

[refsz]

• Bug fix #…?
• New feature?
• BC breaks?
• Tests added?
• Docs added?

I maintain several custom recipes for systems like Drupal, TYPO3, and Shopware. All of them share a common base recipe that defines our standard deploy task workflow. To make this setup more flexible, I would like to introduce an empty group task for deploy:project in the common recipe. This task can then be overridden by specific recipes, for example in a Symfony recipe. However, with the empty() check, the task is never registered; instead, an exception is thrown indicating that the task was not found.

Since the task() function now uses typed parameters, throwing this exception is no longer necessary or possible. Therefore, I have removed it.

Nothing changed in the docs

[refsz]

I’m aware that this would also work without defining the task upfront. However, using empty() in this context does not feel semantically correct to me.