fix(exports): resolve imports with explicit *.js extension

[metonym]

Fixes #1925

Importing using the explicit .*js extension will throw an error as these are not included in the package exports map. Normally, this would be acceptable if it's not part of the API.

However, the optimizeImports Carbon preprocessor rewrites certain imports (e.g., breakpoints) to the source *.js file.

Internal server error: Failed to resolve import "carbon-components-svelte/src/Breakpoint/breakpoints.js" from "src/App.svelte".

[metonym]

Fixed in v0.84.0