fix: Simplify rollup config and remove modulesOnly check that triggers unresolved dependencies error

[marboro92]

Fixes two issues

1. Externals were incorrectly set and should be only peerDependencies
2. We couldn't remove all the extra globals before due to unresolved modules errors, which seem to crop up when using the modulesOnly resolve setting: Using modulesOnly: true triggers unresolved dependency even when target defines module entry rollup/rollup-plugin-node-resolve#200

Description

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Changes include

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• fix: a non-breaking change that solves an issue
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Feature checklist

• Appropriate tests have been added
• Documentation has been updated
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