Remove max limits on dask worker RAM / CPU

Currently, users have to set these manually, so limiting it
to 32 prevents provisioning instances larger than that.

Ref 2i2c-org#291 (comment)

hub-templates/daskhub/values.yaml

@@ -178,8 +178,8 @@ dask-gateway:
                     "environment": options.environment,
                 }
             return Options(
-                Integer("worker_cores", 2, min=1, max=16, label="Worker Cores"),
-                Float("worker_memory", 4, min=1, max=32, label="Worker Memory (GiB)"),
+                Integer("worker_cores", 2, min=1, label="Worker Cores"),
+                Float("worker_memory", 4, min=1, label="Worker Memory (GiB)"),
                 # The default image is set via DASK_GATEWAY__CLUSTER__OPTIONS__IMAGE env variable
                 String("image", label="Image"),
                 Mapping("environment", {}, label="Environment Variables"),