fix: Specify `@preact/signals-core` global to Microbundle

[rschristian]

Closes #398

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🦋 Changeset detected

Latest commit: 686f9c0ee997c4e41b86e200e5a5fdf2fb8cd511

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

| Name | Type | | --------------------- | ----- | | @preact/signals | Patch | | @preact/signals-react | Patch |

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Size Change: 0 B

Total Size: 78 kB

ℹ️ View Unchanged

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