breaking: remove Svelte@3 support

[Svelte 5](https://www.npmjs.com/package/svelte/v/5.0.0) released 10 days ago on `npm` as an official release. This means Svelte 3 is two major versions behind (last released a year ago) and we should no longer support it

### Other

[Cypress 14 breaking changes](https://github.com/cypress-io/cypress/issues/29925)