Add support for arrays in payload.out to fix build errors

[garamond]

When using svelte-preprocess-react with Svelte >5.36.7 the build fails during prerendering.

sveltejs/svelte#16428 which is part of Svelte 5.36.8 causes the build to fail with the error:

[500] GET /
TypeError: html2.substring is not a function

Because of this the Svelte dependency in our project can no longer be upgraded.

This change adds support for arrays in functions handling $$payload. I don't know if this is the right way to address the underlying issue.

[bfanger]

Fixed in 2.1.4, Thanks for reporting the issue and providing the PR.

[webJose]

Tip: Breaking changes should be rolled out as new major versions. Version 2.1.4 will most likely be pulled by projects that use strings, because it satisfies the Semver convention that NPM follows.

v2.1.4 should have been v3.0.0.

[bfanger]

@webJose Only for project that follow semver ;)

The peerDependencies are set for 2.1.4, so updating would result in:

 WARN  Issues with peer dependencies found
.
└─┬ svelte-preprocess-react 2.1.4
  └── ✕ unmet peer svelte@>=5.36.8: found 5.34.0

Besides the issue was introduced in a patch version of svelte as well, so projects that where affected are now fixed too.