fix: align WebAudioContext.decodeAudioData signature with weapp doc

[BH4HPA]

…at docs

Updated the decodeAudioData method in WebAudioContext to match the official WeChat Mini Program documentation:

• Modified the return type to Promise<AudioBuffer> instead of AudioBuffer, because of this method' actual response.
• Adjusted method parameters to accept audioData, successCallback, and errorCallback.

This fixes the TypeScript error and aligns the implementation with the expected API behavior. Closes #17080

这个 PR 做了什么? (简要描述所做更改)
修复了 WebAudioContext.decodeAudioData 的签名

这个 PR 是什么类型? (至少选择一个)

• 错误修复(Bugfix) issue: fix Taro.WebAudioContext.decodeAudioData API 函数签名错误，实现方法不明确 #17080
• 新功能(Feature)
• 代码重构(Refactor)
• TypeScript 类型定义修改(Typings)
• 文档修改(Docs)
• 代码风格更新(Code style update)
• 其他，请描述(Other, please describe):

这个 PR 涉及以下平台:

• 所有小程序
• 微信小程序
• 支付宝小程序
• 百度小程序
• 字节跳动小程序
• QQ 轻应用
• 京东小程序
• 快应用平台（QuickApp）
• Web 平台（H5）
• 移动端（React-Native）
• 鸿蒙（harmony）

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.54%. Comparing base (9477f02) to head (634fd31).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #17081    +/-   ##
========================================
  Coverage   58.54%   58.54%            
========================================
  Files         467      467            
  Lines       27120    27120            
  Branches     5733     5909   +176     
========================================
  Hits        15878    15878            
+ Misses       9922     9866    -56     
- Partials     1320     1376    +56     

Flag	Coverage Δ
taro-cli	73.67% <ø> (ø)
taro-runtime	59.87% <ø> (ø)
taro-web	52.77% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

see 29 files with indirect coverage changes