Use checkout action v4

Signed-off-by: Alban Dericbourg <[email protected]>

Author: adericbourg

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
       contents: read
       packages: write
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: xu-cheng/latex-action@v3
         with:
           root_file: tex/document.tex