Keras clone_model does not work if a concatenate layer with one element to concatenate is used.
Note I also opened an Issue at Keras since I am not sure where its fit better. @benHeid,
Thank you for opening this issue. Development of keras moved to another [repository](https://github.com/keras-team/keras/issues). 

Could you please feel free to close this issue, as this issue is already tracking there in Keras repo.
https://github.com/keras-team/tf-keras/issues/230

 Thank you!
 Are you satisfied with the resolution of your issue?
<a href="https://docs.google.com/forms/d/e/1FAIpQLSfaP12TRhd9xSxjXZjcZFNXPGk4kc1-qMdv3gc6bEP90vY1ew/viewform?entry.85265664=Yes&entry.2137816233=https://github.com/tensorflow/tensorflow/issues/60057">Yes</a>
<a href="https://docs.google.com/forms/d/e/1FAIpQLSfaP12TRhd9xSxjXZjcZFNXPGk4kc1-qMdv3gc6bEP90vY1ew/viewform?entry.85265664=No&entry.2137816233=https://github.com/tensorflow/tensorflow/issues/60057">No</a>

<details><summary>Click to expand!</summary> 
 
 ### Issue Type

Bug

### Have you reproduced the bug with TF nightly?

Yes

### Source

source

### Tensorflow Version

tf 2.13 (nightly)

### Custom Code

No

### OS Platform and Distribution

Windows

### Mobile device

_No response_

### Python version

3.9

### Bazel version

_No response_

### GCC/Compiler version

_No response_

### CUDA/cuDNN version

Na

### GPU model and memory

_No response_

### Current Behaviour?

```shell
If I build a keras model that contains a concatenate layer which only concatenate one element, then the `clone_model` function will fail on that model.

My assumption is that the reason for this behaviour is that the parameter input of this model is a Tensor instead of a List. If I take a look on concatenate layers with multiple inputs, then the input parameter is a list.

I suppose that the error is that the `self._preserve_input_structure_in_config` is not set to true.
```


### Standalone code to reproduce the issue

```shell
from tensorflow.python.keras.layers import Concatenate, Input
from tensorflow.python.keras.models import clone_model, Model

input1 = Input(shape=(1,2), name="input")
concat = Concatenate()([input1])

model = Model(input1, concat)
model.compile()

print("Model exist, now lets try to clone the model..")

cloned_model = clone_model(model) # This line fails
```


### Relevant log output

```shell
...\scratch_2.py", line 12, in <module>
    cloned_model = clone_model(model)

.....

tensorflow\python\keras\layers\merge.py", line 491, in build
    raise ValueError('A `Concatenate` layer should be called '
ValueError: A `Concatenate` layer should be called on a list of at least 1 input.
```
</details>