Cherry pick `Add null tokenizer (11789)` into `r2.1.1`
<!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

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

```
************* Module nemo.collections.nlp.modules.common.tokenizer_utils
nemo/collections/nlp/modules/common/tokenizer_utils.py:73:0: C0301: Line too long (199/119) (line-too-long)
nemo/collections/nlp/modules/common/tokenizer_utils.py:96:0: C0301: Line too long (149/119) (line-too-long)
nemo/collections/nlp/modules/common/tokenizer_utils.py:131:0: C0301: Line too long (146/119) (line-too-long)
nemo/collections/nlp/modules/common/tokenizer_utils.py:226:0: C0301: Line too long (146/119) (line-too-long)
nemo/collections/nlp/modules/common/tokenizer_utils.py:42:0: C0115: Missing class docstring (missing-class-docstring)

-----------------------------------
Your code has been rated at 9.48/10
```

---

Thank you for improving NeMo's documentation! <!-- pylint-output-strict-mode-true -->

beep boop 🤖: 🚨 The following files must be fixed before merge!

---

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

```
************* Module nemo.collections.common.tokenizers.null_tokenizer
nemo/collections/common/tokenizers/null_tokenizer.py:31:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:34:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:38:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:46:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:50:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:54:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:58:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:62:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:66:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:70:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/common/tokenizers/null_tokenizer.py:74:4: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 6.67/10
```

---

Thank you for improving NeMo's documentation! <!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

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

```
************* Module nemo.collections.nlp.modules.common.tokenizer_utils
nemo/collections/nlp/modules/common/tokenizer_utils.py:73:0: C0301: Line too long (199/119) (line-too-long)
nemo/collections/nlp/modules/common/tokenizer_utils.py:96:0: C0301: Line too long (149/119) (line-too-long)
nemo/collections/nlp/modules/common/tokenizer_utils.py:131:0: C0301: Line too long (146/119) (line-too-long)
nemo/collections/nlp/modules/common/tokenizer_utils.py:226:0: C0301: Line too long (146/119) (line-too-long)
nemo/collections/nlp/modules/common/tokenizer_utils.py:42:0: C0115: Missing class docstring (missing-class-docstring)

-----------------------------------
Your code has been rated at 9.48/10
```

---

Thank you for improving NeMo's documentation! [🤖]: Hi @ko3n1g 👋,

We wanted to let you know that a [CICD pipeline](https://github.com/NVIDIA/NeMo/actions/runs/12699554606) for this PR just finished successfully

So it might be time to merge this PR or get some approvals

I'm just a bot so I'll leave it you what to do next.

//cc @pablo-garay @ko3n1g
beep boop [🤖]: Hi @erhoo82 👋,
    
    we've cherry picked #11789 into  for you! 🚀
    
    Please review and approve this cherry pick by your convenience!