chore: use uv build backend

The uv build backend is a great choice for most Python projects. It has
reasonable defaults, with the goal of requiring zero configuration for
most users, but provides flexible configuration to accommodate most
Python project structures. It integrates tightly with uv, to improve
messaging and user experience. It validates project metadata and
structures, preventing common mistakes. And, finally, it's very fast.

uv_build backend was declared stable and ready to use in 0.7.20.
Reference: https://docs.astral.sh/uv/concepts/build-backend/

Signed-off-by: Sébastien Han <seb@redhat.com>

.github/actions/setup-runner/action.yml

@@ -9,11 +9,11 @@ runs:
   using: "composite"
   steps:
     - name: Install uv
-      uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
+      uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
       with:
         python-version: ${{ inputs.python-version }}
         activate-environment: true
-        version: 0.7.6
+        version: 0.7.20
 
     - name: Install dependencies
       shell: bash

.github/workflows/python-build-test.yml

@@ -24,7 +24,7 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
         activate-environment: true
-        version: 0.7.6
+        version: 0.7.20
 
     - name: Build Llama Stack package
       run: |