add a message about unsupported samplers

modules/sd_samplers.py

@@ -28,6 +28,9 @@ def create_sampler(name, model):
 
     assert config is not None, f'bad sampler name: {name}'
 
+    if model.is_sdxl and config.options.get("no_sdxl", False):
+        raise Exception(f"Sampler {config.name} is not supported for SDXL")
+
     sampler = config.constructor(model)
     sampler.config = config