fix: balance Texture2D image dependency references

[Changdw]

Re: cocos/cocos4#267

Changelog

• Backported the Texture2D image dependency reference-count fix to v3.8.9.
• Fixed a reference-count leak when the preload dependency and _mipmaps dependency point to the same ImageAsset.
• After image upload, removes every matching dependency edge and calls decRef() once for each removed edge.
• Kept the cleanup behavior consistent between Web and JSB.
• Added a focused regression test for duplicate ImageAsset dependency cleanup.

Known limitation:

• Compressed textures containing multiple mip levels create derived ImageAsset instances. Releasing references held by the original source asset still requires further handling and is not covered by this backport.

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Continuous Integration

This pull request:

• needs automatic test cases check.

  Manual trigger with @cocos-robot run test cases afterward.

• does not change any runtime related code or build configuration

  If any reviewer thinks the CI checks are needed, please uncheck this option, then close and reopen the issue.

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Compatibility Check

This pull request:

• changes public API, and have ensured backward compatibility with deprecated features.
• affects platform compatibility, e.g. system version, browser version, platform SDK version, platform toolchain, language version, hardware compatibility, etc.
• affects the file structure of the build package or build configuration and requires a user project upgrade.
• introduces breaking changes. If checked, list all changes, affected features, and the scope of the incompatibility.

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[github-actions]

Code Size Check Report

Wechat (WASM)	Before	After	Diff
2D Empty (legacy pipeline)	1009972 bytes	1009993 bytes	⚠️ +21 bytes
2D All (legacy pipeline)	2676439 bytes	2676460 bytes	⚠️ +21 bytes
2D All (new pipeline)	2768175 bytes	2768196 bytes	⚠️ +21 bytes
(2D + 3D) All	10025363 bytes	10025384 bytes	⚠️ +21 bytes

Web (WASM + ASMJS)	Before	After	Diff
(2D + 3D) All	16845507 bytes	16845528 bytes	⚠️ +21 bytes

Interface Check Report

This pull request does not change any public interfaces !

[github-actions]

@Changdw, Please check the result of run test cases:

• Test Platform: PR-Test
• Editor Version: v3.8.9
• Task Result: RUNNING
• Task URL: https://cctest.cocos.org/#/reportview/PR-TEST/7a951eec-8d9f-4b14-8f60-4803a72c779c/-1
• GitHub Action: https://github.com/cocos/cocos-engine/actions/runs/34832152988

Task Details

[github-actions]

@Changdw, Please check the result of run test cases:

• Test Platform: PR-Test
• Editor Version: v3.8.9
• Task Result: PASS
• Task URL: https://cctest.cocos.org/#/reportview/PR-TEST/04d27ebf-82a3-4d9b-b8da-ec96a096c6fe/-1
• GitHub Action: https://github.com/cocos/cocos-engine/actions/runs/34832152988

Task Details