fix test template

ci/unit-test.template.yml

@@ -3,6 +3,7 @@
     services:
       - name: ${BASE_REGISTRY_URL}/db:workspaces
         alias: db
+    image: python:3.10
     script:
         - pip3 install pytest pytest-cov
         - pytest ${CI_PROJECT_DIR}/${SERVICE_NAME}/test --cov=${SERVICE_NAME} --cov-report=html