Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/workflow.yml

@@ -16,7 +16,7 @@ jobs:
     env:
       TZ: Europe/Amsterdam
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v3
         with:
           node-version: 20
@@ -36,7 +36,7 @@ jobs:
     env:
       TZ: Europe/Amsterdam
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v3
         with:
           node-version: 20