Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/docker-build.yml

@@ -11,7 +11,7 @@ jobs:
     name: Docker
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
       - name: Build

.github/workflows/main.yml

@@ -10,7 +10,7 @@ jobs:
     name: Docker
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
       - name: Generate Tag
@@ -60,7 +60,7 @@ jobs:
           --health-timeout 5s
           --health-retries 5
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Test
         run: make test
       - name: Publish Test Report