Optimize test wf

[naik-aakash]

Closes #104

Changes

1. Dropped Python 3.9 from the workflow
2. Uses docker image to speed up test workflows.
3. Packages are now installed using uv (we have further speedup > less time spent in installing dependencies)
4. Fix the issue of coverage files not being uploaded

Example test run times: https://github.com/naik-aakash/autoplex/actions/runs/11000504457

[naik-aakash]

Hi @JaGeo , this could be merged now. All things run as expected. Devcontainer env are also considerably quick to be usable now