fix: remove extra deserialize call for SummaryNetwork

The extra call leads to the DTypePolicy to be deserialized. This is then
passed as a class, and cannot be handled by autoconf, leading to the
error discussed in
#549

Author: vpratz

bayesflow/networks/summary_network.py

@@ -4,7 +4,6 @@
 from bayesflow.types import Tensor
 from bayesflow.utils import layer_kwargs, find_distribution
 from bayesflow.utils.decorators import sanitize_input_shape
-from bayesflow.utils.serialization import deserialize
 
 
 class SummaryNetwork(keras.Layer):
@@ -50,7 +49,3 @@ def compute_metrics(self, x: Tensor, stage: str = "training", **kwargs) -> dict[
                     metrics[metric.name] = metric(outputs, samples)
 
         return metrics
-
-    @classmethod
-    def from_config(cls, config, custom_objects=None):
-        return cls(**deserialize(config, custom_objects=custom_objects))