Fix deprecated local storage invocations

Author: simolus3

drift/lib/src/web/storage.dart

@@ -121,8 +121,7 @@ class _LocalStorageImpl implements DriftWebStorage, CustomSchemaVersionSave {
 
  @override
  int? get schemaVersion {
- final versionStr = _localStorage[_versionKey];
- // ignore: avoid_returning_null
+ final versionStr = _localStorage.getItem(_versionKey);
  if (versionStr == null) return null;
 
  return int.tryParse(versionStr);
@@ -153,7 +152,7 @@ class _LocalStorageImpl implements DriftWebStorage, CustomSchemaVersionSave {
  @override
  Future<void> store(Uint8List data) {
  final binStr = bin2str.encode(data);
- _localStorage[_persistenceKey] = binStr;
+ _localStorage.setItem(_persistenceKey, binStr);
 
  return Future.value();
  }