fix(isolated decl): get the build to run

[lilnasy]

• Continues existing work towards Sync with svelte CLI fork #219
• The build was failing in fork/isolated-decl due to a bug in unbuild.
• Added a workaround.
• CI is green https://github.com/lilnasy/clack/actions/runs/12629968491/job/35188927126

[changeset-bot]

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Latest commit: 7f74eb1

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[natemoo-re]

Hey, long time no see! ❤️

You are amazing and this is amazing. Thank you for contributing and supporting the project—it means a lot!