Bump actions/checkout from 4 to 5

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/build.yml

@@ -23,7 +23,7 @@ jobs:
     # require it, FPC 3.2.0 is not enough.
     container: kambi/castle-engine-cloud-builds-tools:cge-none-fpc331
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - run: cd code-samples/ && make
 
   delphi_test:
@@ -35,7 +35,7 @@ jobs:
         ]
     runs-on: ${{ matrix.host-label }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Delphi Build (Win32)
         run: cd code-samples/ && make all-delphi-win32
       - name: Delphi Build (Win64)