update upload-artifact

Author: matekelemen

.github/workflows/ci.yml

@@ -114,7 +114,7 @@ jobs:
         cd build
         ctest -T memcheck --output-on-failure
 
-    - uses: actions/upload-artifact@v2
+    - uses: actions/upload-artifact@v4
       if: failure()
       with:
         name: "CTest Log Ubuntu C++ & C (${{ matrix.compiler }}-${{ matrix.mpi }})"