fix(webgl): correct buffer-to-texture extent height calculation

[VanityNie]

Use regionTexExtentHeight instead of regionTexExtentWidth when calculating copied texture extents to prevent incorrect row and slice strides.

Re: #

Changelog

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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 file structure of the build package or build configuration which requires user project upgrade.
• introduces breaking changes, please list all changes, affected features and the scope of violation.

[github-actions]

Code Size Check Report

Wechat (WASM)	Before	After	Diff
2D Empty (legacy pipeline)	1015435 bytes	1015436 bytes	⚠️ +1 bytes
2D All (legacy pipeline)	2683166 bytes	2683167 bytes	⚠️ +1 bytes
2D All (new pipeline)	2775425 bytes	2775426 bytes	⚠️ +1 bytes
(2D + 3D) All	10032867 bytes	10032868 bytes	⚠️ +1 bytes

Web (WASM + ASMJS)	Before	After	Diff
(2D + 3D) All	16869285 bytes	16869286 bytes	⚠️ +1 bytes

Interface Check Report

This pull request does not change any public interfaces !

[star-e]

@cocos-robot run test cases

[github-actions]

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

• Test Platform: PR-Test
• Editor Version: v4.0.0
• Task Result: FAIL
• Task URL: https://cctest.cocos.org/#/reportview/PR-TEST/4d01cd42-c7ce-4439-ba8c-2fcbbd979e3b/-1
• GitHub Action: https://github.com/cocos/cocos4/actions/runs/32438478874

Task Details

Platform	build	boot	runned	crashScene	FailScene
web-mobile	PASS	PASS	FAIL		graphics-continuous-filling
ios	PASS	PASS	PASS
mac	PASS	PASS	PASS

[github-actions]

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

• Test Platform: PR-Test
• Editor Version: v4.0.0
• Task Result: PASS
• Task URL: https://cctest.cocos.org/#/reportview/PR-TEST/0dd7568b-dca2-49f0-97a7-b8e043c4ba42/-1
• GitHub Action: https://github.com/cocos/cocos4/actions/runs/32438478874

Task Details