Fix k2 installation in Docker with CUDA 12
# What does this PR do ?

Fix k2 installation in Docker with CUDA 12. 
Currently k2 is not installed in Docker (fails silently).
Relies on a fix in https://github.com/k2-fsa/k2/pull/1200

**Collection**: [ASR]

# Changelog 
- fix k2 installation source in `scripts/speech_recognition/k2/setup.sh`

# Usage

```python
import k2
# do anything you want with k2
```

# Before your PR is "Ready for review"
**Pre checks**:
- [x] Make sure you read and followed [Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md)
- [ ] Did you write any new necessary tests?
- [ ] Did you add or update any necessary documentation?
- [x] Does the PR affect components that are optional to install? (Ex: Numba, Pynini, Apex etc)
  - [ ] Reviewer: Does the PR have correct import guards for all optional libraries?
  
**PR Type**:
- [ ] New Feature
- [x] Bugfix
- [ ] Documentation

If you haven't finished some of the above items you can still open "Draft" PR.


## Who can review?

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# Additional Information
* Related to # (issue)
