Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/test.yml

@@ -4,7 +4,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v2
         with:
           node-version: "16"
@@ -15,7 +15,7 @@ jobs:
     needs: build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v2
         with:
           node-version: "16"
@@ -28,7 +28,7 @@ jobs:
     needs: build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: actions/setup-node@v2
         with:
           node-version: "16"