Is your feature request related to a problem? Please describe

Hi, this is related to the Dokka Gradle plugin, which I would like to help improve.

Improving usage of Gradle would help with the following issues:

• Support Gradle Configuration cache #2231
• Remove double negation in configuration option names #2515
• Gradle 7 incompatibility due to implicit dependency. #1833
• Merge multiproject (composite build) docs #1864
• dokka should provide gradle-idiomatic way to aggregate documentation #1752
• Error: Could not load the value of field values ... found in field dokkaSourceSets of task :dokkaHtml #2612
• Consider supporting Gradle's configuration cache #1217
• dokkaJavadocMultiModule? #1382
• Changes in custom CSS are ignored on incremental documentation rebuild #2286
• Make dokka Gradle task cacheable #830
• Remove the dependency on internal Gradle API #2822
• Bump Gradle to 7.6 #2756
• Use Gradle Worker API #2903

These PRs are related:

• Fix compatibility with Gradle's configuration cache #2499
• Fix configure version eagerly #2799
• Avoid snapshotting sourceLink.localDirectory input #2807
• Fix NoSuchMethodError with Gradle 8.0 RC1 #2816

Describe the solution you'd like

• use Kotlin DSL helpers to make the code more Kotlin-esque, for example
  

  dokka/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/gradleConfigurations.kt

  Line 10 in 8317436

  attributes.attribute(Usage.USAGE_ATTRIBUTE, project.objects.named(Usage::class.java, "java-runtime"))

• Tasks that require downloading files should cache and re-use files Slow documentation generation #2695
• Use configurations for sharing outputs between projects https://docs.gradle.org/7.3/samples/sample_jvm_multi_project_with_code_coverage.html
• Remove non-idiomatic helper functions https://github.com/Kotlin/dokka/blob/master/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/DokkaProperty.kt
• Rename files to match the contents, e.g. https://github.com/Kotlin/dokka/blob/master/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/main.kt
• Remove usages of internal Gradle API classes

  dokka/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/AbstractDokkaLeafTask.kt

  Line 16 in 8317436

  DslObject(this).extensions.add("dokkaSourceSets", container)

• avoid using allprojects {} or subprojects {}
  

  dokka/runners/gradle-plugin/src/test/kotlin/org/jetbrains/dokka/gradle/AbstractDokkaParentTaskTest.kt

  Lines 21 to 23 in 8317436

  	rootProject.subprojects { project ->
  	project.tasks.create<DokkaTask>("dokkaTask")
  	}

  dokka/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/AbstractDokkaParentTask.kt

  Lines 54 to 60 in 8317436

  	fun addSubprojectChildTasks(childTasksName: String) {
  	addChildTasks(project.subprojects, childTasksName)
  	}
  	fun removeSubprojectChildTasks(childTasksName: String) {
  	removeChildTasks(project.subprojects, childTasksName)
  	}

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered

Additional context

Perhaps the dokka team could create a 'gradle-plugin' tag for all relevant GitHub issues? https://github.com/Kotlin/dokka/issues?q=is%3Aissue+is%3Aopen++gradle

Are you willing to provide a PR?

Yes. I will try and split this up into smaller PRs.