Use javac -release and kotlinc -Xjdk-release (#1080)

The change ensures the generated bytecode adheres to the APIs
for the target Java release.

Previously, only sourceCompatibility and targetCompatibility were used,
and they might cause issues like NoSuchMethodError when a newer javac
compiles with -target older_release.

Note: it is good to use a new an up to date javac to avoid issues
in the compiler itself, so having a proper `-release ..` configuration
is vital.

See https://www.morling.dev/blog/bytebuffer-and-the-dreaded-nosuchmethoderr

buildSrc/src/main/kotlin/pklJavaLibrary.gradle.kts

@@ -34,14 +34,9 @@ val libs = the<LibrariesForLibs>()
 val info = project.extensions.getByType<BuildInfo>()
 
 java {
-  val jvmTarget = JavaVersion.toVersion(info.jvmTarget)
-
   withSourcesJar() // creates `sourcesJar` task
   withJavadocJar()
 
-  sourceCompatibility = jvmTarget
-  targetCompatibility = jvmTarget
-
   toolchain {
     languageVersion = info.jdkToolchainVersion
     vendor = info.jdkVendor
@@ -112,10 +107,8 @@ tasks.compileJava {
 }
 
 tasks.withType<JavaCompile>().configureEach {
-  val jvmTarget = JavaVersion.toVersion(info.jvmTarget)
   javaCompiler = info.javaCompiler
-  sourceCompatibility = jvmTarget.majorVersion
-  targetCompatibility = jvmTarget.majorVersion
+  options.release = info.jvmTarget
 }
 
 tasks.withType<JavaExec>().configureEach { jvmArgs(info.jpmsAddModulesFlags) }