Fixed publish guide issue

[rainboyan]

Use Grails 5.0.2 build docs successful, should remove @Nested on macros property.

@Input @Nested Collection macros = []

related commit : 835498f

[tylervz]

@puneetbehl @rainboyan This change should be merged into grails:5.2.x/grails:6.0.x as well, right? I'm currently working on a pull request to update one of the Grails guides to Grails 5.2.1 and I copied the gist "https://raw.githubusercontent.com/grails/grails-guides/master/gradle/guide-build.gradle" into the build.gradle file of the project and the publishGuide Gradle task fails when I have classpath "org.grails:grails-docs:5.2.1" with the error:

A problem was found with the configuration of task ':publishGuide' (type 'PublishGuide').
  - Type 'grails.doc.gradle.PublishGuide' property 'macros' has conflicting type annotations declared: @Input, @Nested.

    Reason: The different annotations have different semantics and Gradle cannot determine which one to pick.

    Possible solution: Choose between one of the conflicting annotations.

But the publishGuide task succeeds when I have classpath "org.grails:grails-docs:5.1.9"

Should I just open two more pull requests to merge this same change into grails:5.2.x and grails:6.0.x?

[rainboyan]

@tylervz sorry for the late reply. I think it's better to merge branch 5.1.x directly into 5.2.x, to ensure that other PRs will not be missing.
@puneetbehl What do you think?

[jdaugherty]

As part of the grails 6.2.x release, we pulled forward this change since it wasn't merged upstream previously.