### 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)

CollisionObject2D *a = Object::cast_to<CollisionObject2D>(p_a.collider);
							CollisionObject2D *b = Object::cast_to<CollisionObject2D>(p_b.collider);
							if (!a || !b) {
								return false;
							}
							int za = a->get_effective_z_index();
							int zb = b->get_effective_z_index();
							if (za != zb) {
								return zb < za;
							}
							return a->is_greater_than(b);
						}
					};
					SortArray<PhysicsDirectSpaceState2D::ShapeResult, ComparatorCollisionObjects> sorter;
					sorter.sort(res, rc);
				}
				for (int i = 0; i < rc; i++) {
					if (res[i].collider_id.is_valid() && res[i].collider) {
						CollisionObject2D *co = Object::cast_to<CollisionObject2D>(res[i].collider);
						if (co && co->can_process()) {
							bool send_event = true;
							if (is_mouse) {
								HashMap<ObjectID, uint64_t>::Iterator F = physics_2d_mouseover.find(res[i].collider_id);
								if (!F) {
									physics_2d_mouseover.insert(res[i].collider_id, frame);
									co->_mouse_enter();
								} else {
									F->value = frame;