fix(storybook): Resetting static dirs when building - FRONT-3789

[planctus]

This removes this error in the build:

(node:6414) UnhandledPromiseRejectionWarning: Error: EEXIST: file already exists, mkdir '/home/runner/work/europa-component-library/europa-component-library/src/playground/ec/build/styles'
(Use `node --trace-warnings ...` to show where the warning was created)
(node:6414) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:6414) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
(node:6414) UnhandledPromiseRejectionWarning: Error: EEXIST: file already exists, mkdir '/home/runner/work/europa-component-library/europa-component-library/src/playground/ec/build/styles'
(node:6414) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)

We are not asking anymore storybook to copy files from the static folders we need when building, basically.

[github-actions]

🚀 Deployed on https://ecl-preview-2682--europa-component-library.netlify.app

[emeryro]

I tried to do a full build after cleaning my folder, and it seems that resources are missing for storybook (running yarn start:eu)

[planctus]

wow, thank god you tested this.. :)