Migrate buildSrc plugins to build-logic

build-logic/build.gradle.kts

@@ -0,0 +1,19 @@
+@Suppress("DSL_SCOPE_VIOLATION") // fixed in Gradle 8.1
+plugins {
+    `kotlin-dsl`
+    alias(libs.plugins.spotless)
+}
+
+dependencies {
+    // this is OK as long as the same version catalog is used in the main build and build-logic
+    // see https://github.com/gradle/gradle/issues/15383#issuecomment-779893192
+    implementation(files(libs.javaClass.superclass.protectionDomain.codeSource.location))
+
+    implementation("com.diffplug.spotless:spotless-plugin-gradle:${libs.plugins.spotless.get().version}")
+}
+
+spotless {
+    kotlin {
+        licenseHeaderFile(rootProject.file("../HEADER.txt"))
+    }
+}