Configure Java source/targetCompatibility to match Kotlin jvmTarget

Otherwise, an error is reported.

Author: Abduqodiri Qurbonzoda

examples/kotlin-kts/build.gradle.kts

@@ -25,6 +25,12 @@ dependencies {
     implementation(project(":kotlinx-benchmark-runtime"))
 }
 
+tasks.withType<JavaCompile> {
+    sourceCompatibility = "1.8"
+    targetCompatibility = "1.8"
+}
+
+
 tasks.withType<KotlinCompile> {
     kotlinOptions {
         jvmTarget = "1.8"

examples/kotlin/build.gradle

@@ -21,6 +21,10 @@ sourceSets.all {
     java.srcDirs = ["$it.name/src"]
     resources.srcDirs = ["$it.name/resources"]
 }
+compileJava {
+    sourceCompatibility = "1.8"
+    targetCompatibility = "1.8"
+}
 
 compileKotlin {
     kotlinOptions.jvmTarget = "1.8"