Fix test by using sets directly with id

Behavior of tensorflow ObjectIdentitySet has change in 2.15,
resulting in the set equality comparing wrappers instead of
wrapped values. See tensorflow/tensorflow@bc28335.

tests/gpflux/layers/test_dedup_trackable_layer.py

@@ -19,7 +19,6 @@
 import pytest
 import tensorflow as tf
 from tensorflow.python.ops.resource_variable_ops import ResourceVariable
-from tensorflow.python.util import object_identity
 
 import gpflow
 from gpflow.utilities import parameter_dict
@@ -141,11 +140,10 @@ def test_weights_equals_deduplicated_parameter_dict(model):
  # We filter out the parameters of type ResourceVariable.
  # They have been added to the model by the `add_metric` call in the layer.
  parameters = [p for p in parameter_dict(model).values() if not isinstance(p, ResourceVariable)]
- variables = map(lambda p: p.unconstrained_variable, parameters)
- deduplicate_variables = object_identity.ObjectIdentitySet(variables)
+ variables = {id(p.unconstrained_variable) for p in parameters}
 
  weights = model.trainable_weights
- assert len(weights) == len(deduplicate_variables)
+ assert len(weights) == len(variables)
 
- weights_set = object_identity.ObjectIdentitySet(weights)
- assert weights_set == deduplicate_variables
+ weights_set = {id(w) for w in weights}
+ assert weights_set == variables