Improves spotlessPredeclare

[bric3]

This PR introduces two changes

• Make spotlessPredeclare visible to Gradle Kotlin DSL type-safe accessors.
• Allow spotlessPredeclare to be used directly without enabling it first in spotless extension.

Now the spotlessPredeclare can be used on the root project directly

spotlessPredeclare {
  java { ... }
}

Or

spotlessPredeclare {
  fromBuildscriptRepositories()
  java { ... }
}

Also fixes #2580

[bric3]

Two jobs failure appear to be infrastructure issues