### Godot version

v4.1.stable.official [970459615]

### System information

Godot v4.1.stable - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1660 Ti (NVIDIA; 31.0.15.3598) - AMD Ryzen 7 3700X 8-Core Processor (16 Threads)

### Issue description

is_input_handled() is returning True, even though set_input_as_handled() has not been called.

Example:
`func _input_event(viewport, event, shape_idx):
	print(viewport.is_input_handled())`

Returns 'True', should return 'False'

### Steps to reproduce

1. Create a new project and add a Node2D as the root
2. Add a child Area2D node containing a CollisionShape2D and a Sprite2D
3. Either create the _input_event(viewport, event, shape_idx) or connect _on_input_event(viewport, event, shape_idx)
4. Print viewport.is_input_handled()
5. True is printed.

### Minimal reproduction project

[input_test.zip](https://github.com/godotengine/godot/files/12063748/input_test.zip)

contact_3d_debug_multimesh = RenderingServer::get_singleton()->multimesh_create();
				RenderingServer::get_singleton()->multimesh_allocate_data(contact_3d_debug_multimesh, get_tree()->get_collision_debug_contact_count(), RS::MULTIMESH_TRANSFORM_3D, false);
				RenderingServer::get_singleton()->multimesh_set_visible_instances(contact_3d_debug_multimesh, 0);
				RenderingServer::get_singleton()->multimesh_set_mesh(contact_3d_debug_multimesh, get_tree()->get_debug_contact_mesh()->get_rid());
				contact_3d_debug_instance = RenderingServer::get_singleton()->instance_create();
				RenderingServer::get_singleton()->instance_set_base(contact_3d_debug_instance, contact_3d_debug_multimesh);
				RenderingServer::get_singleton()->instance_set_scenario(contact_3d_debug_instance, find_world_3d()->get_scenario());
				RenderingServer::get_singleton()->instance_geometry_set_flag(contact_3d_debug_instance, RS::INSTANCE_FLAG_DRAW_NEXT_FRAME_IF_VISIBLE, true);
#endif 
				set_physics_process_internal(true);
			}
		} break;
		case NOTIFICATION_READY: {
#ifndef _3D_DISABLED
			if (audio_listener_3d_set.size() && !audio_listener_3d) {
				AudioListener3D *first = nullptr;
				for (AudioListener3D *E : audio_listener_3d_set) {
					if (first == nullptr || first->is_greater_than(E)) {
						first = E;
					}
				}
				if (first) {
					first->make_current();
				}
			}
			if (camera_3d_set.size() && !camera_3d) {
				
				Camera3D *first = nullptr;
				for (Camera3D *E : camera_3d_set) {
					if (first == nullptr || first->is_greater_than(E)) {