title: gradle jar not including release variant
body: <p>I'm creating a jar containing a cpp library, for use in jni. How can I point out the release version of my library?</p>
  <p>Here is my build.gradle.kts:</p>
  <pre><code>plugins {
    `cpp-library`
    `java-library`
  }
  library {
      targetMachines.add(machines.linux.x86_64)
  }
  tasks.withType(CppCompile::class.java).configureEach {
      compilerArgs.add(&quot;-I/usr/lib/jvm/java-17-openjdk-amd64/include&quot;)
      compilerArgs.add(&quot;-I/usr/lib/jvm/java-17-openjdk-amd64/include/linux&quot;)
  }
  tasks.jar {
      from(library.developmentBinary.flatMap {  (it as CppSharedLibrary).linkFile })
  }
  </code></pre>
  <p>Running <em>./gradlew build</em> will generate a jar containing the debug variant of the so file. How can I get a jar containing the release variant?</p>