chore: speed up whl install in cli tests with uv (#4764)

uv for whl install

.github/workflows/python_test.yml

@@ -145,13 +145,16 @@ jobs:
         if: steps.check-version.outputs.skipped == 'false'
         run: |
           make build main=true
-      - name: Install wheel
+      - name: Install wheel and Test CLI
         if: steps.check-version.outputs.skipped == 'false'
         run: |
-          python -m pip install dist/*.whl
+          uv venv new-venv
+          source new-venv/bin/activate
+          uv pip install dist/*.whl
       - name: Test CLI
         if: steps.check-version.outputs.skipped == 'false'
         run: |
+          source new-venv/bin/activate
           python -m langflow run --host 127.0.0.1 --port 7860 --backend-only &
           SERVER_PID=$!
           # Wait for the server to start