Sort zip in exporter (#2311)

Might fix
google/osv-scanner#1007 (comment)

Sort the entries before adding to the zip archive.

docker/exporter/exporter.py

@@ -102,6 +102,7 @@ def _export_ecosystem_to_bucket(self, ecosystem: str, tmp_dir: str):
 
     zip_path = os.path.join(tmp_dir, 'all.zip')
     with zipfile.ZipFile(zip_path, 'w', zipfile.ZIP_DEFLATED) as zip_file:
+      files_to_zip = []
 
       @ndb.tasklet
       def _export_to_file_and_zipfile(bug):
@@ -112,15 +113,18 @@ def _export_to_file_and_zipfile(bug):
         file_path = os.path.join(tmp_dir, bug.id() + '.json')
         vulnerability = yield bug.to_vulnerability_async(include_source=True)
         osv.write_vulnerability(vulnerability, file_path)
-        # Tasklets are not truly multiple threads;they are actually
-        # event loops, which makes it safe to write to ZIP files."
-        # Details: https://cloud.google.com/appengine/docs/legacy/
-        # standard/python/ndb/async#tasklets
-        zip_file.write(file_path, os.path.basename(file_path))
 
+        files_to_zip.append(file_path)
+
+      # This *should* pause here until
+      # all the exports have been written to disk.
       osv.Bug.query(
           osv.Bug.ecosystem == ecosystem).map(_export_to_file_and_zipfile)
 
+      files_to_zip.sort()
+      for file_path in files_to_zip:
+        zip_file.write(file_path, os.path.basename(file_path))
+
     with concurrent.futures.ThreadPoolExecutor(
         max_workers=_EXPORT_WORKERS) as executor:
       # Note: all.zip is included here