fix: fix closing ws connection

[qevolg]

Description

Fix closing ws connection

Jira: https://jira.taosdata.com:18080/browse/TD-37771

Checklist

Please check the items in the checklist if applicable.

• Is the user manual updated?
• Are the test cases passed and automated?
• Is there no significant decrease in test coverage?

[Copilot]

Pull Request Overview

This PR fixes WebSocket connection handling by addressing a circular reference issue that prevented proper connection cleanup when WsTaos instances are dropped.

• Changes the connection management function to use a weak reference to WsTaos instead of a strong reference
• Adds a test to verify that dropping a WsTaos instance properly closes the WebSocket connection
• Adds proper state management in the WsTaos Drop implementation

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
taos-ws/src/query/conn.rs	Modified run function to accept Weak<WsTaos> parameter and added safety checks when accessing WsTaos methods; added new test for connection cleanup
taos-ws/src/query/asyn.rs	Updated to pass weak reference to connection handler and added state cleanup in Drop implementation

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 95.87629% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 82.57%. Comparing base (0c9b05a) to head (7d8905e).

Files with missing lines	Patch %	Lines
taos-ws/src/query/conn.rs	95.78%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #501      +/-   ##
==========================================
- Coverage   82.63%   82.57%   -0.07%     
==========================================
  Files         117      117              
  Lines       56703    56790      +87     
==========================================
+ Hits        46857    46892      +35     
- Misses       9846     9898      +52     

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