Fix typo in ci.yml workflow

Author: vhscampos

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
   markdown-link-check:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@4.1.7
+    - uses: actions/checkout@v4.1.7
     - uses: gaurav-nelson/github-action-markdown-link-check@v1
       with:
           config-file: '.github/workflows/markdown-link-check.json'