Move KotlinCompile configuration to convention (#325)

Author: whyoleg

build-logic/src/main/kotlin/kotlinx/io/conventions/kotlinx-io-multiplatform.gradle.kts

@@ -20,6 +20,11 @@ plugins {
 }
 
 kotlin {
+    @OptIn(ExperimentalKotlinGradlePluginApi::class)
+    compilerOptions {
+        allWarningsAsErrors.set(true)
+        freeCompilerArgs.add("-Xexpect-actual-classes")
+    }
 
     val versionCatalog: VersionCatalog = extensions.getByType<VersionCatalogsExtension>().named("libs")
     jvmToolchain {
@@ -33,6 +38,14 @@ kotlin {
         testRuns["test"].executionTask.configure {
             useJUnitPlatform()
         }
+        // can be replaced with just `compilerOptions { }` in Kotlin 2.0
+        compilations.configureEach {
+            compileTaskProvider.configure {
+                compilerOptions {
+                    freeCompilerArgs.add("-Xjvm-default=all")
+                }
+            }
+        }
     }
 
     js {

build.gradle.kts

@@ -24,28 +24,6 @@ allprojects {
     }
 }
 
-subprojects {
-    tasks.withType<KotlinCompile>().configureEach {
-        kotlinOptions {
-            allWarningsAsErrors = true
-            freeCompilerArgs += "-Xjvm-default=all"
-            freeCompilerArgs += "-Xexpect-actual-classes"
-        }
-    }
-    tasks.withType<KotlinNativeCompile>().configureEach {
-        kotlinOptions {
-            allWarningsAsErrors = true
-            freeCompilerArgs += "-Xexpect-actual-classes"
-        }
-    }
-    tasks.withType<KotlinJsCompile>().configureEach {
-        kotlinOptions {
-            allWarningsAsErrors = true
-            freeCompilerArgs += "-Xexpect-actual-classes"
-        }
-    }
-}
-
 @OptIn(ExperimentalBCVApi::class)
 apiValidation {
     ignoredProjects.add("kotlinx-io-benchmarks")