Jackspeak pinned to prevent build errors

[Jackspeak](https://www.npmjs.com/package/jackspeak) is currently pinned to version 2.1.1 with `resolutions` in `package.json` to prevent errors building Storybook with Yarn (see [why](https://github.com/canonical/react-components/pull/1159#discussion_r1919218580)). 2.1.1 is 2 years old at this point.

Storybook has an [issue](https://github.com/storybookjs/storybook/issues/22431) tracking this and we are using their workaround for now, but we should move to newer versions of Jackspeak once the underlying issue is resolved and the Storybook issue is closed.