bump to 5.4.0

CHANGELOG.md

-# 6.0.0
-* JVM target升级至17
-* 修复Lint问题
-* 删除web相关的
+# 5.4.0
+* 增加鸿蒙分享网页和小程序，微信sdk升级1.0.6
 
 # 5.3.1
 * JVM target降低至11

pubspec.yaml

 name: fluwx
 description: The capability of implementing WeChat SDKs in Flutter. With Fluwx, developers can use WeChatSDK easily, such as sharing, payment, lanuch mini program and etc.
-version: 6.0.0
+version: 5.4.0
 homepage: https://github.com/OpenFlutter/fluwx
 
 environment: