CI: Update actions/checkout: v4->v6.0.2

Author: bastelfreak

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
       BUNDLE_WITHOUT: development:system_tests:release
       PUPPET_GEM_VERSION: ">= 7.0"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6.0.2
       - name: Setup ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -49,7 +49,7 @@ jobs:
       PUPPET_VERSION: "~> ${{ matrix.puppet }}.0"
     name: Puppet ${{ matrix.puppet }} (Ruby ${{ matrix.ruby }})
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6.0.2
       - name: Setup ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -71,7 +71,7 @@ jobs:
         include: ${{fromJson(needs.setup_matrix.outputs.puppet_beaker_test_matrix)}}
     name: "${{ matrix.name }}"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6.0.2
       - name: Setup ruby
         uses: ruby/setup-ruby@v1
         with: