feat(ci): switch to astral-sh/setup-uv for Python setup and use uv pip for package installation

[bhimrazy]

What does this PR do?

This PR updates the CI testing setup to use uv for faster installation. - (1/n)

Note: This PR does not yet include updates to the pyproject.toml.

Inspired from Lightning-AI/LitServe#563

Installation time reduced (~ 2-5 m) as follows:

OS	Python Version	Before	After (with uv)
ubuntu	3.11	install - 2m 45s test - 37m 8s	install - 9s test - 34m 59s
ubuntu	3.12	install - 2m 43s test - 48m 16s	install - 11s test - 46m 3s
mac-os	3.10	install - 1m 19s test - 32m 49s	install - 12s test - 35m 26s
mac-os	3.11	install - 1m 52s test - 35m 26s	install - 10s test - 34m 3s
windows	3.11	install - 5m 15s test - 21m 56s	install - 20s test - 21m 45s
windows	3.12	install - 5m 14s test - 27m 24s	install - 19s test - 26m 8s

Ref Runs: before & after

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in GitHub issues there's a high chance it will not be merged.

Did you have fun?

Make sure you had fun coding 🙃

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83%. Comparing base (fa2020e) to head (92499fc).
Report is 1 commits behind head on main.

Additional details and impacted files

@@         Coverage Diff         @@
##           main   #656   +/-   ##
===================================
  Coverage    83%    83%           
===================================
  Files        49     49           
  Lines      6812   6812           
===================================
+ Hits       5686   5688    +2     
+ Misses     1126   1124    -2     

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[deependujha]

Nice.

Also tried make setup in lightning-studio with uv. Super fast!⚡️