List files in build/regress.

For debugging LD_PRELOAD failure.
diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index ca1e314..928d16e 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -30,5 +30,5 @@
       - name: test
         working-directory: ${{runner.workspace}}/build
         run: |
-          (cd regress; ./liboverride-test -v) || true
+          (cd regress; ./liboverride-test -v; find . -print) || true
           ctest -v