Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/cd.yml

@@ -31,7 +31,7 @@ jobs:
 
     steps:
       - name: Checkout repo and submodules
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive
 

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
 
     steps:
       - name: Checkout repo and submodules
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive
 
@@ -43,7 +43,7 @@ jobs:
 
     steps:
       - name: Checkout repo and submodules
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive