chore(spec2cdk): assertTruthy error message typo (#26792)

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Author: 0o001

tools/@aws-cdk/spec2cdk/lib/cdk/union-ordering.ts

@@ -114,7 +114,7 @@ function requiredPropertyNames(t: TypeDefinition): Set<string> {
 
 function assertTruthy<T>(x: T): NonNullable<T> {
   if (x == null) {
-    throw new Error('Expected truhty value');
+    throw new Error('Expected truthy value');
   }
   return x;
-}
+}