Remove NO_THREADS fallback code, Godot 4 requires thread support

This also removes `OS::can_use_threads` from the public API since it's always
true.

1 files changed, 1 insertions, 6 deletions

diff --git a/scene/3d/navigation_region_3d.cpp b/scene/3d/navigation_region_3d.cpp
index b060d314ba..06182d921c 100644
--- a/scene/3d/navigation_region_3d.cpp
+++ b/scene/3d/navigation_region_3d.cpp
@@ -261,12 +261,7 @@ void NavigationRegion3D::bake_navigation_mesh(bool p_on_thread) {
 	BakeThreadsArgs *args = memnew(BakeThreadsArgs);
 	args->nav_region = this;
 
-	if (p_on_thread && !OS::get_singleton()->can_use_threads()) {
-		WARN_PRINT("NavigationMesh bake 'on_thread' will be disabled as the current OS does not support multiple threads."
-				   "\nAs a fallback the navigation mesh will bake on the main thread which can cause framerate issues.");
-	}
-
-	if (p_on_thread && OS::get_singleton()->can_use_threads()) {
+	if (p_on_thread) {
 		bake_thread.start(_bake_navigation_mesh, args);
 	} else {
 		_bake_navigation_mesh(args);