Nightly build looking for pre-release tag on pypi

[evaline-ju]

Describe the bug

Currently vllm 0.9.0 is tagged as a pre-release on Github, but the nightly build and test automation added in #67 is looking for the pypi release (that does not exist yet).

Sample Code

Actions: https://github.com/foundation-model-stack/vllm-detector-adapter/actions/runs/15101382022

Expected behavior

There may be a gap between pre-release time and pypi release. Either use github tag or pypi release as the sources of truth.

Observed behavior

Failures on missing release