Build: Fix warnings in pill

Required for Gradle 7+ #KTI-559

plugins/pill/pill-importer/src/JpsCompatiblePluginTasks.kt

@@ -6,10 +6,11 @@
 package org.jetbrains.kotlin.pill
 
 import org.gradle.api.Project
-import org.gradle.api.plugins.BasePluginConvention
-import org.gradle.api.plugins.JavaPluginConvention
+import org.gradle.api.plugins.BasePluginExtension
+import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.api.tasks.SourceSet
 import org.gradle.kotlin.dsl.extra
+import org.gradle.kotlin.dsl.getByType
 import org.jetbrains.kotlin.pill.artifact.ArtifactDependencyMapper
 import org.jetbrains.kotlin.pill.artifact.ArtifactGenerator
 import org.jetbrains.kotlin.pill.model.PDependency
@@ -304,10 +305,10 @@ class JpsCompatiblePluginTasks(private val rootProject: Project, private val pla
 
             for (path in DIST_LIBRARIES) {
                 val project = rootProject.findProject(path) ?: error("Project '$path' not found")
-                val archiveName = project.convention.findPlugin(BasePluginConvention::class.java)!!.archivesBaseName
+                val archiveName = project.extensions.getByType<BasePluginExtension>().archivesName.get()
                 val classesJars = listOf(File(distLibDir, "$archiveName.jar")).filterExisting()
                 val sourcesJars = listOf(File(distLibDir, "$archiveName-sources.jar")).filterExisting()
-                val sourceSets = project.convention.findPlugin(JavaPluginConvention::class.java)!!.sourceSets
+                val sourceSets = project.extensions.getByType<JavaPluginExtension>().sourceSets
 
                 val applicableSourceSets = listOfNotNull(
                     sourceSets.findByName(SourceSet.MAIN_SOURCE_SET_NAME),

plugins/pill/pill-importer/src/ModelParser.kt

@@ -3,19 +3,22 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
+@file:Suppress("DEPRECATION") // Suppress deprecation warning of HasConvention
+
 package org.jetbrains.kotlin.pill
 
 import org.gradle.api.Project
 import org.gradle.api.artifacts.Configuration
 import org.gradle.api.tasks.*
 import org.gradle.api.plugins.JavaPlugin
-import org.gradle.api.plugins.JavaPluginConvention
+import org.gradle.api.plugins.JavaPluginExtension
 import org.gradle.plugins.ide.idea.IdeaPlugin
 import org.gradle.api.file.SourceDirectorySet
 import org.gradle.api.internal.HasConvention
 import org.gradle.api.internal.file.copy.CopySpecInternal
 import org.gradle.api.internal.file.copy.SingleParentCopySpec
 import org.gradle.jvm.tasks.Jar
+import org.gradle.kotlin.dsl.findByType
 import org.gradle.language.jvm.tasks.ProcessResources
 import org.jetbrains.kotlin.pill.model.POrderRoot.*
 import org.jetbrains.kotlin.pill.model.PSourceRoot.*
@@ -330,6 +333,6 @@ val Project.pillModuleName: String
 
 val Project.sourceSets: SourceSetContainer?
     get() {
-        val convention = project.convention.findPlugin(JavaPluginConvention::class.java) ?: return null
-        return convention.sourceSets
+        val javaExtension = project.extensions.findByType<JavaPluginExtension>() ?: return null
+        return javaExtension.sourceSets
     }