Fix: update python versions be 3.9 and greater to avoid pytorch dependency issues

[lalanikarim]

Python 3.8 results in pytorch version incompatibility issue

$ uv run --python 3.8 --with=git+https://github.com/resemble-ai/chatterbox https://raw.githubusercontent.com/resemble-ai/chatterbox/refs/heads/master/example_tts.py
  × No solution found when resolving `--with` dependencies:
  ╰─▶ Because torch==2.6.0 has no wheels with a matching Python implementation tag (e.g., `cp38`) and chatterbox-tts==0.1.2 depends on torch==2.6.0,
      we can conclude that chatterbox-tts==0.1.2 cannot be used.
      And because only chatterbox-tts==0.1.2 is available and you require chatterbox-tts, we can conclude that your requirements are unsatisfiable.

      hint: You require CPython 3.8 (`cp38`), but we only found wheels for `torch` (v2.6.0) with the following Python implementation tags: `cp39`,
      `cp310`, `cp311`, `cp312`, `cp313`

[undg]

This solves the same issue when installing all dependencies with poetry:

$ poetry install
  Updating dependencies
  Resolving dependencies... (0.2s)

  The current project\'s supported Python range (>=3.8) is not compatible with some of the required packages Python requirement:
    - torch requires Python >=3.9.0, so it will not be installable for Python >=3.8,<3.9.0

  Because chatterbox-tts depends on torch (2.6.0) which requires Python >=3.9.0, version solving failed.

    * Check your dependencies Python requirement: The Python requirement can be specified via the `python` or `markers` properties

      For torch, a possible solution would be to set the `python` property to ">=3.9.0"

      https://python-poetry.org/docs/dependency-specification/#python-restricted-dependencies,
      https://python-poetry.org/docs/dependency-specification/#using-environment-markers