Update actions/checkout action to v7

Author: renovate[bot]

.github/workflows/pr.yml

@@ -8,7 +8,7 @@ jobs:
   vagrant-syntax:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: '4.0.6'
@@ -29,7 +29,7 @@ jobs:
     env:
       OPENVOX_GEM_VERSION: ${{matrix.openvox.openvox_version}}
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{matrix.openvox.ruby_version}}
@@ -57,7 +57,7 @@ jobs:
     env:
       OPENVOX_GEM_VERSION: ${{matrix.openvox.openvox_version}}
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{matrix.openvox.ruby_version}}
@@ -69,7 +69,7 @@ jobs:
   yamllint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - name: Install yamllint
         run: pip install 'yamllint>=1,<2'
       - name: Run yamllint