ci: fix typo causing failure

Author: ryanpholt

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-    - uses: actions/checkout@v4
+      uses: actions/checkout@v4
 
     - name: Setup Neovim
       uses: rhysd/action-setup-vim@v1