Bug: sniffio dependency is not installed

[jorgeecardona]

Description

Hi,

I just got the following error:

E                 File "/usr/local/lib/python3.14/site-packages/litestar/concurrency.py", line 8, in <module>
E                   import sniffio
E               ModuleNotFoundError: No module named 'sniffio'

I noticed that the sniffio is not in the documentation either is installed when litestar is installed, I have to install it manually, but the import is not conditional.

Shouldn't this import be treated differently?

Let me know I would to help with my first simple PR with this great project.

Thank you,

URL to code causing the issue

No response

MCVE

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Logs

Package Version

litestar.version
Version(major=2, minor=18, patch=0, release_level='final', serial=0)

Platform

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[LeGmask]

I have the same issue on my project

[sloria]

This is a dupe of litestar-org/litestar#4505 and was fixed in litestar