chore(deps): update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/build.yml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           submodules: true
 
@@ -71,7 +71,7 @@ jobs:
 
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           submodules: true
 

.github/workflows/docs.yml

@@ -11,7 +11,7 @@ jobs:
 
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - uses: actions/cache@v3
         with: