Refactor Python setup step in test workflow to use 'uv python install'

.gitea/workflows/run_tests.yml

@@ -18,10 +18,8 @@ jobs:
         enable-cache: true
         cache-dependency-glob: "uv.lock"
 
-    - name: "Set up Python"
-      uses: actions/setup-python@v5
-      with:
-        python-version-file: "pyproject.toml"
+    - name: Set up Python
+      run: uv python install
 
     - name: Install the project
       run: uv sync --locked --all-extras --dev