Exclude stories from dts generations

[florianduros]

Exclude storybook stories from dts generation:

1. It's useless
2. Generate error like:

[vite:dts] Start generate declaration files...
src/resize/separator/SeparatorView.stories.tsx:117:37 - error TS2339: Property 'toMatchImageSnapshot' does not exist on type 'Assertion<HTMLElement>'.

117         await expect(canvasElement).toMatchImageSnapshot();
                                        ~~~~~~~~~~~~~~~~~~~~
src/resize/separator/SeparatorView.stories.tsx:150:37 - error TS2339: Property 'toMatchImageSnapshot' does not exist on type 'Assertion<HTMLElement>'.

150         await expect(canvasElement).toMatchImageSnapshot();
                                        ~~~~~~~~~~~~~~~~~~~~