AssignmentFile => Adapt to ImmutableFileDescriptor zod format

types/Dojo/AssignmentFile.ts

-import { ImmutableFileDescriptor, immutableFileDescriptorSchema } from './ImmutableFileDescriptor';
-import { z }                                                      from 'zod';
+import ImmutableFileDescriptor from './ImmutableFileDescriptor';
+import { z }                   from 'zod';
 
 
 const AssignmentFile = z.object({
                                     dojoAssignmentVersion: z.number(),
                                     version              : z.number(),
-                                    immutable            : z.array(immutableFileDescriptorSchema.transform(value => value as ImmutableFileDescriptor)),
+                                    immutable            : z.array(ImmutableFileDescriptor.transform(value => value as ImmutableFileDescriptor)),
                                     result               : z.object({
                                                                         container: z.string(),
                                                                         volume   : z.string().optional()