fix :github actions test demo

Author: xuzhu

.github/workflows/github-actions-demo.yml

@@ -17,4 +17,4 @@ jobs:
         run: |
           ls ${{ github.workspace }}
       - run: echo "🍏 This job's status is ${{ job.status }}."
-      - run：echo "This job's finished "
+      - run: echo "This job's finished "