Bump actions/checkout from 3 to 6 (#859)

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -14,7 +14,7 @@ jobs:
   complement-internal:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3 # Checkout complement
+      - uses: actions/checkout@v6 # Checkout complement
       - uses: actions/setup-go@v6
         with:
           go-version-file: go.mod
@@ -54,7 +54,7 @@ jobs:
             timeout: 10m
 
     steps:
-      - uses: actions/checkout@v3 # Checkout complement
+      - uses: actions/checkout@v6 # Checkout complement
 
       - uses: actions/setup-go@v6
         with: