Merge Dokkatoo into Dokka Gradle Plugin (#3695)

Initial Dokkatoo import

- merge DGP-classic into dokka-gradle-plugin
- add flag to toggle between DPG-classic and Dokkatoo
- Update Dokkatoo code to be Java-8 compatible
- update dokkatoo package name
- stop using `org.jetbrains.dokka.gradle.utils.sourceLink_` - weird class-not-found compilation issue
- update TaskPathCollector workaround
- fix LogHtmlPublicationLinkTask - use Http instead of Https connection
- Specify language/api as Kotlin 1.4 for dokka-gradle-plugin (to be compatible with Gradle 7)
- update api dump
- update formatting, add copyright header
- remove duplicated 'Isolation' from WorkerIsolation subtypes, & fix test
- renaming 'Dokkatoo' to 'Dokka'...
- fix process isolation worker jvm args
- add 'min supported Gradle' warning
- lazily fetch DokkaGradlePluginMode from `project.extra.properties`
- fixing KotlinNativeDistributionAccessor...
- fix DGP group/version
- add copyright header
- Change BCV to official BCV
- fix `toLowerCase()` deprecation
- remove `dokka-gradle-plugin` from `libs.versions.toml` (it's no longer used)
- remove duplicated plugin website/vcsUrl, move tags into specific Dokka plugin
- exclude Gradle's embedded-dependencies from DGP
- remove extraneous leftover groups

Author: adam-enko

build-logic/build.gradle.kts

@@ -13,7 +13,6 @@ kotlin {
 }
 
 dependencies {
-    implementation(libs.gradlePlugin.dokka)
     implementation(libs.gradlePlugin.kotlin)
     implementation(libs.gradlePlugin.shadow)
     implementation("org.gradle.kotlin:gradle-kotlin-dsl-plugins:$expectedKotlinDslPluginsVersion")

build-logic/src/main/kotlin/dokkabuild.gradle-plugin.gradle.kts

@@ -2,34 +2,35 @@
  * Copyright 2014-2024 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import dokkabuild.utils.excludeGradleEmbeddedDependencies
+import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
 
 plugins {
     id("org.gradle.kotlin.kotlin-dsl")
     id("dokkabuild.java")
-    kotlin("jvm")
     id("dokkabuild.publish-gradle-plugin")
 }
 
-// org.gradle.kotlin.kotlin-dsl sets languageVersion and apiVersion to 1.8 by default starting from Gradle 8.
-// As we need to be compatible with previous Gradle versions, we need to set it back to 1.4.
-// Note: we should do it directly on tasks and not via top-level `kotlin.compilerOptions`
-//       because `kotlin-dsl plugin` declares them on task level, and so top-level config is overridden
-tasks.withType<KotlinCompile>().configureEach {
+kotlin {
     compilerOptions {
-        languageVersion = dokkaBuild.kotlinLanguageLevel
-        apiVersion = dokkaBuild.kotlinLanguageLevel
+        // Must use Kotlin 1.4 to support Gradle 7
+        languageVersion = @Suppress("DEPRECATION") KotlinVersion.KOTLIN_1_4
+        apiVersion = @Suppress("DEPRECATION") KotlinVersion.KOTLIN_1_4
+    }
+}
 
-        freeCompilerArgs.addAll(
-            // need 1.4 support, otherwise there might be problems
-            // with Gradle 6.x (it's bundling Kotlin 1.4)
-            "-Xsuppress-version-warnings",
-            "-Xjsr305=strict",
-            "-Xskip-metadata-version-check",
-        )
+tasks.compileKotlin {
+    compilerOptions {
+        // `kotlin-dsl` plugin overrides the versions at the task level,
+        // which takes priority over the `kotlin` project extension.
+        // So, fix it by manually setting the LV per-task.
+        languageVersion.set(kotlin.compilerOptions.languageVersion)
+        apiVersion.set(kotlin.compilerOptions.apiVersion)
     }
 }
 
 tasks.validatePlugins {
     enableStricterValidation = true
 }
+
+excludeGradleEmbeddedDependencies(sourceSets.main)