Add save-artifacts step to CI workflow

Add step to save build artifacts after testing.

Author: Halicea

.github/workflows/c-cpp.yml

@@ -18,3 +18,11 @@ jobs:
       run: make
     - name: test
       run: make test
+    - name: save-artifacts
+  
+      uses: actions/upload-artifact@v6.0.0
+      with:
+        name: hed
+        path: ./build/*
+        include-hidden-files: true
+