improve performance

[star-e]

Fix performance problem of custom pipeline. Reducing calls of getXXXLights.
Improve performance of render graph construction. Empty unordered_map from msvc will allocate memory, which causes performance problem.

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]

Interface Check Report

! WARNING this pull request has changed these public interfaces:

@@ -65124,8 +65124,12 @@
             depthSlotName: string;
             shadowPass: any;
             forwardPass: any;
             postProcess: postProcess.PostProcess | undefined;
+            maxSpotLights: number;
+            maxSphereLights: number;
+            maxPointLights: number;
+            maxRangedDirLights: number;
             setClearFlag(clearFlag: gfx.ClearFlagBit): _cocos_rendering_post_process_utils_pass_context__PassContext;
             setClearColor(x: number, y: number, z: number, w: number): _cocos_rendering_post_process_utils_pass_context__PassContext;
             setClearDepthColor(x: number, y: number, z: number, w: number): _cocos_rendering_post_process_utils_pass_context__PassContext;
             version(): _cocos_rendering_post_process_utils_pass_context__PassContext;