ci: update checkout to v4

Author: clintonsteiner

.github/workflows/test.yml

@@ -24,7 +24,7 @@ jobs:
         - linkcheck
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Set up Python
         uses: actions/setup-python@v4

.github/workflows/translation.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
     - name: Grab the repo src
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         fetch-depth: 0  # To reach the common commit
     - name: Set up git user as [bot]