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>

Author: dependabot[bot]

.github/workflows/run_tests_matlab.yml

@@ -36,7 +36,7 @@ jobs:
         release: ${{matrix.version}}
 
     - name: Install CPP_ROI
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         submodules: true
         fetch-depth: 0

.github/workflows/validate_cff.yml

@@ -21,7 +21,7 @@ jobs:
 
     steps:
 
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         fetch-depth: 1