Update actions/checkout action to v6

Author: renovate-bot

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3.6.0
+      - uses: actions/checkout@v6.0.0
 
       - uses: actions/setup-node@v3.9.1
         with:

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3.6.0
+      - uses: actions/checkout@v6.0.0
       - uses: actions/setup-node@v3.9.1
         with:
           node-version: 18.x