fix(okhttp): address review feedback on virtual-thread dispatcher test suite

- Replace javaLauncher override with testJvmConstraints so lower-JDK
  shards skip vthread21Test rather than forcing JDK 21
- Drop OkHttp 4.x from AsyncCallInstrumentation.knownMatchingTypes()
  until test coverage exists; trim stale 4.x javadoc
- Remove ThreadPerTaskExecutorVirtualThreadTest (no OkHttp dependency,
  belongs in a separate PR)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: dougqh

dd-java-agent/instrumentation/java/java-concurrent/java-concurrent-21.0/src/test/java/ThreadPerTaskExecutorVirtualThreadTest.java

@@ -23,8 +23,8 @@ tasks.named("compileVthread21TestJava", JavaCompile) {
 }
 
 tasks.named("vthread21Test", Test) {
-  javaLauncher = javaToolchains.launcherFor {
-    languageVersion = JavaLanguageVersion.of(21)
+  testJvmConstraints {
+    minJavaVersion = JavaVersion.VERSION_21
   }
 }
 

dd-java-agent/instrumentation/okhttp/okhttp-3.0/build.gradle

@@ -27,14 +27,8 @@
  * caller who actually enqueued this AsyncCall. Result: under concurrent OkHttp load, {@code
  * okhttp.request} spans cross-contaminate between traces.
  *
- * <p>The class moved between OkHttp 3.x and 4.x:
- *
- * <ul>
- *   <li>OkHttp 3.x &mdash; {@code okhttp3.RealCall$AsyncCall}
- *   <li>OkHttp 4.x &mdash; {@code okhttp3.internal.connection.RealCall$AsyncCall}
- * </ul>
- *
- * Both are inner classes of {@code RealCall} and both transitively implement {@link Runnable}.
+ * <p>{@code AsyncCall} is an inner class of {@code RealCall} and transitively implements {@link
+ * Runnable}.
  */
 @AutoService(InstrumenterModule.class)
 public final class AsyncCallInstrumentation extends InstrumenterModule.Tracing
@@ -51,8 +45,7 @@ public AsyncCallInstrumentation() {
   @Override
   public String[] knownMatchingTypes() {
     return new String[] {
-      "okhttp3.RealCall$AsyncCall", // OkHttp 3.x
-      "okhttp3.internal.connection.RealCall$AsyncCall", // OkHttp 4.x
+      "okhttp3.RealCall$AsyncCall",
     };
   }