In a medium saucepan, melt the butter over medium-high heat. Add the flour and stir constantly until a wet, sand-like texture forms, 3-5 minutes. Stir in the garlic powder, onion powder, mustard powder, and Worcestershire sauce; cook for another 30 seconds. Add the milk and beer and whisk until smooth. Bring to a simmer and cook until thickened, 30-60 seconds more.