fix: fetch data directories before CI tests

.github/workflows/validate.yml

@@ -142,6 +142,14 @@ jobs:
         continue-on-error: true
         run: python scripts/export_native.py --all --fetch --output-dir "$RUNNER_TEMP/native"
 
+      # A pack built without its data directories exits non-zero: it is not
+      # the pack a user gets. Tests that build packs need the same trees a
+      # release build has, as deploy-site.yml fetches them.
+      - name: Fetch the data directories
+        run: python scripts/refresh_data_dirs.py
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Run test suite
         # No test downloads a release asset: 252 MB files fetched into the
         # shared cache filled the runner's disk and changed what later tests