adjusting MaybeAddJakartaServletApi to be a ScanningRecipe so that …

[nmck257]

…it can correctly apply its precondition to the AddDependency recipe

What's your motivation?

closes #254

Any additional context

Thinking about the introduction of ScanningRecipes, this is an example of a recipe which "wants" to be a non-scanning recipe but is trying to call a ScanningRecipe, and therefore itself becomes a ScanningRecipe

Checklist

• I've added unit tests to cover both positive and negative cases
• I've added the license header to any new files through ./gradlew licenseFormat
• I've used the IntelliJ auto-formatter on affected files
• [ ] I've updated the documentation (if applicable)

[nmck257]

thanks @sambsnyd -- the build has passed and i don't have write access here if you're good to merge this, too