Bump actions/checkout from 5.0.0 to 6.0.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5.0.0...v6.0.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/pr_validation.yml

@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: actions/checkout@v5.0.0
+        uses: actions/checkout@v6.0.0
         with:
           lfs: true
           fetch-depth: 0

.github/workflows/publish_nuget.yml

@@ -16,7 +16,7 @@ jobs:
 
     steps:
     - name: "Checkout"
-      uses: actions/checkout@v5.0.0
+      uses: actions/checkout@v6.0.0
       with:
         lfs: true
         fetch-depth: 0