chore: replace List<@nullable Object> with List<?>

The latter is easier to read, and it forbids list.add(...) at the compile-time.

See https://jspecify.dev/docs/user-guide/#wildcard-bounds

Author: vlsi

junit-jupiter-params/src/main/java/org/junit/jupiter/params/aggregator/ArgumentsAccessor.java

@@ -198,7 +198,7 @@ public interface ArgumentsAccessor {
 	/**
 	 * Get all arguments in this accessor as an immutable list.
 	 */
-	List<@Nullable Object> toList();
+	List<?> toList();
 
 	/**
 	 * Get the index of the current test invocation.

junit-jupiter-params/src/main/java/org/junit/jupiter/params/aggregator/DefaultArgumentsAccessor.java

@@ -139,7 +139,7 @@ public int size() {
 	}
 
 	@Override
-	public List<@Nullable Object> toList() {
+	public List<?> toList() {
 		return Collections.unmodifiableList(Arrays.asList(this.arguments));
 	}
 

junit-platform-commons/src/main/java/org/junit/platform/commons/support/AnnotationSupport.java

@@ -443,7 +443,7 @@ public static List<Field> findAnnotatedFields(Class<?> clazz, Class<? extends An
 	 * @see ReflectionSupport#tryToReadFieldValue(Field, Object)
 	 */
 	@API(status = MAINTAINED, since = "1.4")
-	public static List<@Nullable Object> findAnnotatedFieldValues(Object instance,
+	public static List<?> findAnnotatedFieldValues(Object instance,
 			Class<? extends Annotation> annotationType) {
 		Preconditions.notNull(instance, "instance must not be null");
 
@@ -476,7 +476,7 @@ public static List<Field> findAnnotatedFields(Class<?> clazz, Class<? extends An
 	 * @see ReflectionSupport#tryToReadFieldValue(Field, Object)
 	 */
 	@API(status = MAINTAINED, since = "1.4")
-	public static List<@Nullable Object> findAnnotatedFieldValues(Class<?> clazz,
+	public static List<?> findAnnotatedFieldValues(Class<?> clazz,
 			Class<? extends Annotation> annotationType) {
 
 		List<Field> fields = findAnnotatedFields(clazz, annotationType, ModifierSupport::isStatic,

junit-platform-commons/src/main/java/org/junit/platform/commons/util/ReflectionUtils.java

@@ -656,7 +656,7 @@ public static <T> Try<Object> tryToReadFieldValue(Class<T> clazz, String fieldNa
 	 * @return an immutable list of the values of the specified fields; never
 	 * {@code null} but may be empty or contain {@code null} entries
 	 */
-	public static List<@Nullable Object> readFieldValues(List<Field> fields, @Nullable Object instance) {
+	public static List<?> readFieldValues(List<Field> fields, @Nullable Object instance) {
 		return readFieldValues(fields, instance, field -> true);
 	}
 
@@ -673,7 +673,7 @@ public static <T> Try<Object> tryToReadFieldValue(Class<T> clazz, String fieldNa
 	 * @return an immutable list of the values of the specified fields; never
 	 * {@code null} but may be empty or contain {@code null} entries
 	 */
-	public static List<@Nullable Object> readFieldValues(List<Field> fields, @Nullable Object instance,
+	public static List<?> readFieldValues(List<Field> fields, @Nullable Object instance,
 			Predicate<Field> predicate) {
 		Preconditions.notNull(fields, "fields list must not be null");
 		Preconditions.notNull(predicate, "Predicate must not be null");