Making TDT models support all-positive durations (previously duration must contain 0)
@hainan-xv Something is wrong with tests in this branch (not related to TDT). Please, update to main and toggle `Run CICD` label This PR is stale because it has been open for 14 days with no activity. Remove stale label or comment or update or this will be closed in 7 days. @hainan-xv This still an IP? This PR is stale because it has been open for 14 days with no activity. Remove stale label or comment or update or this will be closed in 7 days. This PR was closed because it has been inactive for 7 days since being marked as stale. Addressed review comments. @artbataev @tbartley94  This PR is stale because it has been open for 14 days with no activity. Remove stale label or comment or update or this will be closed in 7 days. This PR is stale because it has been open for 14 days with no activity. Remove stale label or comment or update or this will be closed in 7 days. @hainan-xv let's get this merged if there's nothing you want to add This PR is stale because it has been open for 14 days with no activity. Remove stale label or comment or update or this will be closed in 7 days. This PR is stale because it has been open for 14 days with no activity. Remove stale label or comment or update or this will be closed in 7 days. <!-- 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.

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

```
************* Module nemo.collections.asr.parts.numba.rnnt_loss.utils.cuda_utils.gpu_rnnt_kernel
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:745:0: C0301: Line too long (121/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:856:0: C0301: Line too long (134/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:913:0: C0301: Line too long (124/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:980:0: C0301: Line too long (125/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:995:0: C0301: Line too long (123/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:1183:0: C0301: Line too long (128/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:1189:0: C0301: Line too long (145/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:1194:0: C0301: Line too long (132/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:1208:0: C0301: Line too long (142/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:1383:0: C0301: Line too long (144/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:1394:0: C0301: Line too long (162/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:1410:0: C0301: Line too long (167/119) (line-too-long)
nemo/collections/asr/parts/numba/rnnt_loss/utils/cuda_utils/gpu_rnnt_kernel.py:68:0: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.64/10
```

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Thank you for improving NeMo's documentation!
# What does this PR do ?

This PR makes TDT models support all-positive durations (previously duration must contain 0).

**Collection**: [ASR]

# Changelog 
- the kernal code for computing TDT loss is changed. 
- tests are added to test the correctness of new code and also ensures it's back-compatible.

# Usage
N/A

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