AttributeError: module 'exca.steps.base' has no attribute 'NoValue' when importing TribeModel in Google Colab (Python 3.12)

I am encountering an import error when trying to use tribev2 in a fresh Google Colab environment.

Environment
Platform: Google Colab
Python: 3.12.x
Package: tribev2
Code
```
from tribev2.demo_utils import TribeModel, download_file
from tribev2.plotting import PlotBrain
from pathlib import Path

```
Error

`AttributeError:` module 'exca.steps.base' has no attribute 'NoValue'`

Full Traceback
```
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
/tmp/ipykernel_1818/3387571854.py in ()
----> 1 from tribev2.demo_utils import TribeModel, download_file
2 from tribev2.plotting import PlotBrain
3 from pathlib import Path
4
5 CACHE_FOLDER = Path("./cache")

...

/usr/local/lib/python3.12/dist-packages/neuralset/events/study.py in StudyLoader()
253 return chain._run(*args)
254
--> 255 def run(self, value: tp.Any = exca.steps.base.NoValue()) -> tp.Any:
256 """Execute -- bypass Step-level caching when transforms exist
257 (the internal chain handles it)."""

AttributeError: module 'exca.steps.base' has no attribute 'NoValue'
```

Reproduce the import in a fresh Python 3.12 Google Colab environment using tribev2.demo_utils and tribev2.plotting. Read neuralset/events/study.py around line 255 and inspect the exca.steps.base.NoValue reference; done means both imports complete without the reported AttributeError.

Written by the indexing model from the issue text.