Bump actions/checkout from 5 to 6 (#6401)

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Kim Kulling <kimkulling@users.noreply.github.com>

.github/workflows/ccpp.yml

@@ -48,7 +48,7 @@ jobs:
     - name: ccache
       uses: hendrikmuhs/ccache-action@v1.2
       
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
           submodules: true
           

.github/workflows/cd.yml

@@ -27,7 +27,7 @@ jobs:
             os: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: lukka/get-cmake@latest
 

.github/workflows/sanitizer.yml

@@ -14,7 +14,7 @@ jobs:
     name: adress-sanitizer
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: lukka/get-cmake@latest    
     - uses: lukka/set-shell-env@v1
       with:
@@ -38,7 +38,7 @@ jobs:
     name: undefined-behavior-sanitizer
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: lukka/get-cmake@latest    
     - uses: lukka/set-shell-env@v1
       with:
@@ -62,7 +62,7 @@ jobs:
     name: printf-sanitizer
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     
     - name: run scan_printf script
       run: ./scripts/scan_printf.sh