ci: List current directory structure to aid debugging failing CI

End-to-end tests fail as `/_app/immutable/workers/assets/smithereens_bg.wasm` can not be found so using `tree -fhD` to
list the current directory structure to see where the files are.

Locally they are in two locations (likely only one is being used!)

```
(pgfinder2024) ❱ fd smithereens_bg.wasm
web/smithereens/pkg/smithereens_bg.wasm
web/smithereens/pkg/smithereens_bg.wasm.d.ts
web/src/lib/pkg/smithereens_bg.wasm
web/src/lib/pkg/smithereens_bg.wasm.d.ts
```

.github/workflows/e2e-checks.yml

@@ -35,4 +35,6 @@ jobs:
         run: pnpm exec playwright install --with-deps
 
       - name: Run Playwright Tests
-        run: pnpm test
+        run: |
+          tree -fhD     # Looking for location of smithereens_bg.wasm
+          pnpm test