Fix missing constructor for spine.String & SkeletonBounds

[bofeng-song]

Re: #
#17002
cocos/cocos-engine-external#453

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:

@@ -51250,8 +51250,10 @@
          */
         /* eslint @typescript-eslint/no-explicit-any: "off" */
         export namespace spine {
             export class String {
+                constructor(name: string, own: boolean);
+                constructor(val: spine.String);
                 length: number;
                 isEmpty: boolean;
                 strPtr: number;
                 str: string;