build(deps): bump actions/checkout from 6 to 7

Bumps [actions/checkout](https://github.com/actions/checkout) from 6 to 7.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v6...v7)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/_test-existing-project.yml

@@ -47,7 +47,7 @@ jobs:
             "${{ matrix.magento }}" test-project
 
       - name: Checkout devcontainer
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           path: test-project/.devcontainer/magento2-devcontainer
 

.github/workflows/ci.yml

@@ -96,7 +96,7 @@ jobs:
         run: npm install -g @devcontainers/cli
 
       - name: Checkout devcontainer
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           path: .devcontainer/magento2-devcontainer
 

.github/workflows/deploy-docs.yml

@@ -28,7 +28,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           fetch-depth: 0
       - name: Setup Node

.github/workflows/sync-starter.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout starter repo
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           repository: graycoreio/magento2-devcontainer-starter
           token: ${{ secrets.GRAYCORE_GITHUB_TOKEN }}