ci: upload tests build output as job artifacts

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>

Author: theihor

.github/workflows/test.yml

@@ -44,3 +44,10 @@ jobs:
 
     - name: Test SHARED=${{ matrix.shared }}
       run: make -C tests test
+
+    - uses: actions/upload-artifact@v4
+      if: always()
+      with:
+        name: tests-output
+        if-no-files-found: warn
+        path: tests/.output