chore: Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

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

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

.github/workflows/continuous-integration.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: "ubuntu-latest"
     steps:
       - name: "Checkout repository"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@v4"
       - name: "Set up PHP"
         uses: "shivammathur/setup-php@v2"
         with:
@@ -36,7 +36,7 @@ jobs:
           - "v2"
     steps:
       - name: "Checkout repository"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@v4"
       - name: "Install expect"
         run: |
           sudo apt-get update
@@ -59,7 +59,7 @@ jobs:
     runs-on: "ubuntu-latest"
     steps:
       - name: "Checkout repository"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@v4"
       - name: "Install expect"
         run: |
           sudo apt-get update
@@ -90,7 +90,7 @@ jobs:
     runs-on: "ubuntu-latest"
     steps:
       - name: "Checkout repository"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@v4"
       - name: "Run shellcheck"
         run: "shellcheck --exclude=SC2230 bin/*.sh tests/*.sh"
 
@@ -117,7 +117,7 @@ jobs:
           - ""
     steps:
       - name: "Checkout repository"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@v4"
       - name: "Set up PHP"
         uses: "shivammathur/setup-php@v2"
         with:
@@ -248,7 +248,7 @@ jobs:
           - "v2"
     steps:
       - name: "Checkout repository"
-        uses: "actions/checkout@v3"
+        uses: "actions/checkout@v4"
       - name: "Set up PHP"
         uses: "shivammathur/setup-php@v2"
         with: