arthas-all-3.7.3

https://github.com/alibaba/arthas/issues?q=is%3Aclosed+milestone%3A3.7.3

• #2900 在 arthas 3.x 版本的打包结果里，同时有 as.sh/as3.sh , arthas-boot.jar/arthas-boot3.jar ，保持兼容性
• #2884 feat: restrict boot to use 3.x version and support website version switching