add checkout repo to action job

.gitea/workflows/test_action.yaml

@@ -6,6 +6,9 @@ jobs:
   Python3:
     runs-on: ubuntu-latest
     steps:
-      - run: echo "Hello World"
+      - name: checkout repo
-      - run: python -V
+        uses: actions/checkout@v4
-      - run: ls .
+      - name: check python version
+        run: python -V
+      - name: access image housed by lfs
+        run: md5sum data/images/220px-George_the_amazing_guinea_pig.jpg