Updating Actions to use uv.

Author: AllynH

.github/workflows/validate-csv.yml

@@ -27,8 +27,8 @@ jobs:
 
     - name: Install dependencies
       run: |
-        python -m pip install --upgrade pip
-        pip install pytest==9.0.1
+        python -m pip install --upgrade uv
+        uv pip install -r requirements.txt
         
     - name: Run CSV validation tests
       run: |