[debug] find libstdc++ in actions

Author: MilesCranmer

.github/workflows/main.yml

@@ -76,6 +76,8 @@ jobs:
           python -m pip install --upgrade tox
       - name: Install PyCall
         run: python ci/install_pycall.py
+      - name: Find libstdc++
+        run: find / -name libstdc++.so.6
       - name: Run test
         run: python -m tox -- --verbose --cov=julia
         env: