Shape issue in `reverb`

## 🐛 Bug

reverb fails with "ValueError: cannot reshape array of size 20000 into shape (10000,)"

https://github.com/facebookresearch/AugLy/blob/0bcfe4e34343cf2b3bfa1999a2f68df312212296/augly/audio/functional.py#L1082-L1083

## To Reproduce
```
augly.audio.functional.reverb(np.random.uniform(-1, 1, (1, 10_000)))
```

## Expected behavior

I expect the function to return an array of shape `(1, 10_000)`

## Environment

- AugLy Version: 1.0.0
- OS (e.g., Linux): Linux
- How you installed AugLy: `pip install augly`
- Python version: 3.10.9
- Other relevant packages (Tensorflow, etc): torchaudio 0.13.0+cu116 (also tested with 0.12.1)

Start at augly/audio/functional.py lines 1082-1083 and reproduce the failure with the provided np.random.uniform input. Trace the reshape and verify that reverb returns an array with shape (1, 10,000) without raising the reported ValueError.

Written by the indexing model from the issue text.