Upgrade gradle plugins

build.gradle.kts

@@ -1,6 +1,6 @@
 plugins {
-    id("org.jetbrains.intellij") version "0.6.5"
-    kotlin("jvm") version "1.4.10"
+    id("org.jetbrains.intellij") version "1.3.0"
+    id("org.jetbrains.kotlin.jvm") version "1.5.10"
 }
 
 val pluginVersion: String by project
@@ -19,10 +19,10 @@ dependencies {
 
 // See https://github.com/JetBrains/gradle-intellij-plugin/
 intellij {
-    version = platformVersion
+    version.set(platformVersion)
 }
 tasks.getByName<org.jetbrains.intellij.tasks.PatchPluginXmlTask>("patchPluginXml") {
-    changeNotes("""
+    changeNotes.set("""
       <h3>[1.2]</h3>
 
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