Bump actions/checkout from 4 to 6

.github/workflows/auto-merge.yml

@@ -8,7 +8,7 @@ jobs:
   auto-merge:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: ahmadnassri/action-dependabot-auto-merge@v2
         with:
           target: patch

.github/workflows/bundler-audit.yml

@@ -7,7 +7,7 @@ jobs:
   audit:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: "Bundler Audit"
         uses: thoughtbot/bundler-audit-action@main
         env:

.github/workflows/rspec-tests.yml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Install Ruby and gems
         uses: ruby/setup-ruby@v1
         with:

.github/workflows/standardrb.yml

@@ -12,7 +12,7 @@ jobs:
       checks: write
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: StandardRB Linter
         uses: standardrb/standard-ruby-action@v1.5.0
         env: