Simplify parallel execution configuration docs due to JDK 17 requirement

Author: marcphilipp

documentation/src/docs/asciidoc/user-guide/writing-tests.adoc

@@ -3436,9 +3436,9 @@ executing tests will not exceed the configured parallelism. For example, when us
 of the synchronization mechanisms described in the next section, the `ForkJoinPool` that
 is used behind the scenes may spawn additional threads to ensure execution continues with
 sufficient parallelism.
-If you require such guarantees, with Java 9+, it is possible to limit the maximum number
-of concurrent threads by controlling the maximum pool size of the `dynamic`, `fixed` and
-`custom` strategies.
+If you require such guarantees, it is possible to limit the maximum number of concurrent
+threads by controlling the maximum pool size of the `dynamic`, `fixed` and `custom`
+strategies.
 
 [[writing-tests-parallel-execution-config-properties]]
 ===== Relevant properties

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/Constants.java

@@ -272,8 +272,6 @@ public final class Constants {
 	 * {@value #PARALLEL_CONFIG_FIXED_PARALLELISM_PROPERTY_NAME}; defaults to
 	 * {@code 256 + fixed.parallelism}.
 	 *
-	 * <p>Note: This property only takes affect on Java 9+.
-	 *
 	 * @since 5.10
 	 */
 	@API(status = MAINTAINED, since = "5.13.3")
@@ -290,8 +288,6 @@ public final class Constants {
 	 *
 	 * <p>Value must either {@code true} or {@code false}; defaults to {@code true}.
 	 *
-	 * <p>Note: This property only takes affect on Java 9+.
-	 *
 	 * @since 5.10
 	 */
 	@API(status = MAINTAINED, since = "5.13.3")