fix: improve fallbacks

[benmccann]

Vite defines conditions when bundling and the fallback is only hit when not bundling, so the import.meta.env.DEV doesn't do anything and can be removed

Conditions should be set during bundling. We can update rollup-plugin-svelte and svelte-loader to enforce that they are. Users should always have one of either development or production set. If neither are set, then we know something is wrong. We also know something is wrong in the svelte plugins if the the svelte condition doesn't get set

The fallbacks can't be tree-shaken, but can only be hit when not bundling in which case we don't need tree-shaking anyway

[changeset-bot]

🦋 Changeset detected

Latest commit: b161767

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

This PR includes changesets to release 1 package

Name	Type
esm-env	Patch

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