upgrade dependencies

lib/src/crypto/key_encrypter_kdf.dart

@@ -3,7 +3,7 @@ import 'dart:typed_data';
 
 import 'package:argon2_ffi_base/argon2_ffi_base.dart';
 import 'package:crypto/crypto.dart' as crypto;
-import 'package:isolate/isolate_runner.dart';
+import 'package:isolates/isolate_runner.dart';
 import 'package:kdbx/kdbx.dart';
 import 'package:kdbx/src/utils/byte_utils.dart';
 import 'package:kdbx/src/kdbx_var_dictionary.dart';

pubspec.yaml

@@ -12,13 +12,15 @@ dependencies:
 #  path: ^1.6.0
   logging: '>=0.11.3+2 <2.0.0'
   crypto: '>=2.0.0 <4.0.0'
-  pointycastle: '>=1.0.1 <4.0.0'
+  pointycastle: '>=3.0.0 <4.0.0'
   xml: '>=4.4.0 <6.0.0'
   uuid: ">=3.0.0 <5.0.0"
   meta: '>=1.0.0 <2.0.0'
   clock: '>=1.0.0 <2.0.0'
   convert: '>=2.0.0 <4.0.0'
-  isolate: '>=2.0.3 <3.0.0'
+  #isolate: '>=2.0.3 <3.0.0'
+  # using forked null safety release until it is merged https://github.com/dart-lang/isolate/pull/45
+  isolates: '>=3.0.0 <4.0.0'
   path: '>=1.6.0 <2.0.0'
   quiver: '>=2.1.0 <4.0.0'
   archive: '>=2.0.13 <4.0.0'