Suppress NullableOptional, as we already do in, e.g., Truth.assertThat(Optional).

RELNOTES=n/a
PiperOrigin-RevId: 609047209

Author: cpovirk

core/src/main/java/com/google/common/truth/GuavaOptionalSubject.java

@@ -30,10 +30,14 @@
  * @author Christian Gruber
  */
 public final class GuavaOptionalSubject extends Subject {
+  @SuppressWarnings("NullableOptional") // Truth always accepts nulls, no matter the type
   private final @Nullable Optional<?> actual;
 
   GuavaOptionalSubject(
-      FailureMetadata metadata, @Nullable Optional<?> actual, @Nullable String typeDescription) {
+      FailureMetadata metadata,
+      @SuppressWarnings("NullableOptional") // Truth always accepts nulls, no matter the type
+          @Nullable Optional<?> actual,
+      @Nullable String typeDescription) {
     super(metadata, actual, typeDescription);
     this.actual = actual;
   }

core/src/main/java/com/google/common/truth/OptionalSubject.java

@@ -30,11 +30,13 @@
 @SuppressWarnings("Java7ApiChecker") // used only from APIs with Java 8 in their signatures
 @IgnoreJRERequirement
 public final class OptionalSubject extends Subject {
+  @SuppressWarnings("NullableOptional") // Truth always accepts nulls, no matter the type
   private final @Nullable Optional<?> actual;
 
   OptionalSubject(
       FailureMetadata failureMetadata,
-      @Nullable Optional<?> subject,
+      @SuppressWarnings("NullableOptional") // Truth always accepts nulls, no matter the type
+          @Nullable Optional<?> subject,
       @Nullable String typeDescription) {
     super(failureMetadata, subject, typeDescription);
     this.actual = subject;