Remove some TODOs from tests after upstream JDT Core fixes

Signed-off-by: Alexander Kriegisch <Alexander@Kriegisch.name>

tests/features1919/java19/SwitchPatternPreview3OK.java

@@ -157,7 +157,7 @@ public class SwitchPatternPreview3OK {
    *   https://bugs.eclipse.org/bugs/show_bug.cgi?id=579360
    *   https://github.com/eclipse-jdt/eclipse.jdt.core/issues/587
    *
-   * TODO: reactivate when implemented or move to preview 4 with Java 20.
+   * DONE: reactivated after fix in Java 21
    */
   /*
   sealed interface I<T> permits A, B {}

tests/features1920/java20/SwitchPatternPreview4OK.java

@@ -130,7 +130,7 @@ public class SwitchPatternPreview4OK {
    *   https://bugs.eclipse.org/bugs/show_bug.cgi?id=579360
    *   https://github.com/eclipse-jdt/eclipse.jdt.core/issues/587
    *
-   * TODO: reactivate when implemented or move to preview 5 with Java 21.
+   * DONE: reactivated after fix in Java 21
    */
 /*
   sealed interface I<T> permits D, E {}

tests/features1921/java21/SwitchPatternPreview4OK.java

@@ -129,8 +129,6 @@ public class SwitchPatternPreview4OK {
    *   https://openjdk.java.net/jeps/420#2--Exhaustiveness-of-switch-expressions-and-statements
    *   https://bugs.eclipse.org/bugs/show_bug.cgi?id=579360
    *   https://github.com/eclipse-jdt/eclipse.jdt.core/issues/587
-   *
-   * TODO: reactivate when implemented or move to preview 5 with Java 21.
    */
   sealed interface I<T> permits D, E {}
   final static class D<X> implements I<String> {}

tests/features199/java18/SwitchPatternPreview2OK.java

@@ -97,6 +97,8 @@ public class SwitchPatternPreview2OK {
    *   https://openjdk.java.net/jeps/420#2--Exhaustiveness-of-switch-expressions-and-statements
    *   https://bugs.eclipse.org/bugs/show_bug.cgi?id=579360
    *   https://github.com/eclipse-jdt/eclipse.jdt.core/issues/587
+   *
+   *   DONE: reactivated after fix in Java 21
    */
   /*
   sealed interface I<T> permits A, B {}