Add pynini to Docker container
# What does this PR do ?

Install `pynini` library in Docker container. 
Currently pynini is not installed in Docker container, which causes TTS models to crash

**Collection**: [Note which collection this PR will affect]
* text processing
* tts

# Changelog 
- install pynini (`Dockerfile`)

# Problem
Run the following code in container built from `r1.11.0` branch:
```python
from nemo.collections.tts.models import FastPitchModel
model = FastPitchModel.from_pretrained("tts_en_fastpitch_multispeaker")
```
*Expected results:* model is loaded correctly
*Actual result:*
```
AttributeError                            Traceback (most recent call last)
File /opt/conda/lib/python3.8/site-packages/hydra/_internal/utils.py:583, in _locate(path)
    582 try:
--> 583     obj = getattr(obj, part)
    584 except AttributeError as exc_attr:
AttributeError: module 'nemo_text_processing.text_normalization' has no attribute 'normalize'

During handling of the above exception, another exception occurred:
ModuleNotFoundError                       Traceback (most recent call last)
File /opt/conda/lib/python3.8/site-packages/hydra/_internal/utils.py:589, in _locate(path)
    588 try:
--> 589     obj = import_module(mod)
    590     continue
File /opt/conda/lib/python3.8/importlib/__init__.py:127, in import_module(name, package)
    126         level += 1
--> 127 return _bootstrap._gcd_import(name[level:], package, level)
File <frozen importlib._bootstrap>:1014, in _gcd_import(name, package, level)
File <frozen importlib._bootstrap>:991, in _find_and_load(name, import_)
File <frozen importlib._bootstrap>:975, in _find_and_load_unlocked(name, import_)
File <frozen importlib._bootstrap>:671, in _load_unlocked(spec)
File <frozen importlib._bootstrap_external>:843, in exec_module(self, module)
File <frozen importlib._bootstrap>:219, in _call_with_frames_removed(f, *args, **kwds)
File /opt/conda/lib/python3.8/site-packages/nemo_text_processing/text_normalization/normalize.py:24, in <module>
     22 from typing import Dict, List, Union
---> 24 import pynini
     25 import regex
ModuleNotFoundError: No module named 'pynini'
```

# 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?

Anyone in the community is free to review the PR once the checks have passed. 
[Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md) contains specific people who can review PRs to various areas.

# Additional Information
* Related to #4674
