Bug: Version parsing error when handling torchaudio==2.6.0+cu126

### Describe the bug

When installing or updating a custom node with a dependency like `torchaudio==2.6.0+cu126`, the ComfyUI-Manager throws the following error:

invalid literal for int() with base 10: '0+cu126'

This is due to attempting to parse the version string `'2.6.0+cu126'` as a dot-separated string and converting its patch version to `int()`, which fails because `'0+cu126'` is not a valid integer.

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### Steps to reproduce

1. Use a custom node with `requirements.txt` that includes `torchaudio>=0.13.0`
2. Ensure `torchaudio==2.6.0+cu126` is already installed
3. Let ComfyUI-Manager attempt dependency installation
4. Observe error

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### Expected behavior

ComfyUI-Manager should correctly parse PEP 440-compliant version strings such as `2.6.0+cu126` using a robust method, such as `packaging.version.parse`, instead of string splitting + `int()`.

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### Proposed fix

Use `packaging.version` for safe version parsing:

```python
from packaging import version

v = version.parse("2.6.0+cu126")
v.major # 2
v.minor # 6
v.micro # 0

This would allow the Manager to handle CUDA-tagged builds of PyTorch packages (like torch, torchaudio, torchvision, etc.) without crashing.