[CI} clean uv cache at end (#2794)

Author: CSY-ModelCloud

.github/workflows/unit_tests_reusable.yml

@@ -120,7 +120,8 @@ jobs:
 
       - name: Activate uv env
         run: |
-          printenv | grep UV
+          
+          uv cache prune --ci
           
           bash .github/scripts/ci_unit_activate_uv_env.sh \
             "${{ matrix.test_script }}" \
@@ -238,3 +239,5 @@ jobs:
           rm -rf ./* .[^.] .??* || true
           echo "cleaning venv: ${{ env.VIRTUAL_ENV }}"
           rm -rf "${{ env.VIRTUAL_ENV }}"
+          echo "Cleaning uv cache"
+          uv cache prune --ci