Remove default mutable arguments from AbstractEmbModel constructor
<!-- pylint-output-strict-mode-false -->

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---

Your code was analyzed with PyLint. The following annotations have been identified:

```
************* Module nemo.collections.diffusion.encoders.conditioner
nemo/collections/diffusion/encoders/conditioner.py:22:0: C0115: Missing class docstring (missing-class-docstring)
nemo/collections/diffusion/encoders/conditioner.py:40:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/diffusion/encoders/conditioner.py:44:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/diffusion/encoders/conditioner.py:48:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/diffusion/encoders/conditioner.py:75:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/diffusion/encoders/conditioner.py:133:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/diffusion/encoders/conditioner.py:138:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/diffusion/encoders/conditioner.py:169:0: C0115: Missing class docstring (missing-class-docstring)
nemo/collections/diffusion/encoders/conditioner.py:185:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/diffusion/encoders/conditioner.py:190:4: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.06/10
```

---

Thank you for improving NeMo's documentation!
# What does this PR do ?

This changes the constructor signature. This change is backwards compatible with existing callers. 

**Collection**: [Note which collection this PR will affect]
Diffusion for NeMo2

# Changelog 
- Remove default mutable arguments from `AbstractEmbModel` constructor

# Usage
* You can potentially add a usage example below

```python
# Add a code snippet demonstrating how to use this 
```

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# Additional Information
* Related to # (issue)
