Remove Python 3.8 support

[Natim]

• I understand that this repository is auto-generated and my pull request may not be merged

Changes being requested

Remove Python 3.8 support, since the dependency tree doesn't support it anymore.

Additional context & links

"jiter>=0.10.0, <1",

This version of jiter is not compatible with Python 3.8

  × No solution found when resolving dependencies for split (markers: python_full_version == '3.8.*'):
  ╰─▶ Because the requested Python version (>=3.8) does not satisfy Python>=3.9 and jiter>=0.10.0 depends on Python>=3.9, we can conclude that jiter>=0.10.0 cannot be used.
      And because only the following versions of jiter are available:
          jiter<=0.10.0
          jiter==0.11.0
          jiter==0.11.1
      we can conclude that jiter>=0.10.0 cannot be used.
      And because your project depends on jiter>=0.10.0 and your project requires openai[aiohttp], we can conclude that your project's requirements are unsatisfiable.

      hint: The `requires-python` value (>=3.8) includes Python versions that are not supported by your dependencies (e.g., jiter>=0.10.0 only supports >=3.9). Consider using a more
      restrictive `requires-python` value (like >=3.9).

      hint: While the active Python version is 3.9, the resolution failed for other Python versions supported by your project. Consider limiting your project's supported Python versions
      using `requires-python`.