fix(custom-pipeline) addLight() func, return byte offset error

[troublemaker52025]

Re: #

Changelog

• @en When an added light source is present, the returned buffer byte offset is incorrect
• @zh 当添加的光源存在时，返回的缓冲区字节偏移位置错误
• fix: scene culling light造成UBO无法对齐 cocos-engine#19156

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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.

[troublemaker52025]

@cocos-robot run test cases

[github-actions]

Code Size Check Report

Wechat (WASM)	Before	After	Diff
2D Empty (legacy pipeline)	1014459 bytes	1014459 bytes	✅ 0 bytes
2D All (legacy pipeline)	2681984 bytes	2681984 bytes	✅ 0 bytes
2D All (new pipeline)	2773753 bytes	2773761 bytes	⚠️ +8 bytes
(2D + 3D) All	10030969 bytes	10030977 bytes	⚠️ +8 bytes

Web (WASM + ASMJS)	Before	After	Diff
(2D + 3D) All	16867382 bytes	16867390 bytes	⚠️ +8 bytes

Interface Check Report

This pull request does not change any public interfaces !

[github-actions]

@troublemaker52025, 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/22d2a899-1926-42c4-b93c-c51611cd1823/-1
• GitHub Action: https://github.com/cocos/cocos4/actions/runs/28164697916

Task Details

[github-actions]

@troublemaker52025, 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/9485d538-da2f-459c-9aa7-7cf7f865e491/-1
• GitHub Action: https://github.com/cocos/cocos4/actions/runs/28164697916

Task Details

[github-actions]

@troublemaker52025 ❗ There was an error during the execution of the tasks. Please check the logs for more details.