GHA: Update to latest actions/checkout

Author: Lectem

.github/workflows/cmake.yml

@@ -20,7 +20,7 @@ jobs:
     env:
       BUILD_TYPE: ${{ matrix.buildtype }}
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
       with:
         submodules: 'recursive'