Migrate @storybook/addon-outline to strict TS

[kyletsang]

Part of #22176

What I did

Migrate @storybook/addon-outline to strict TS. There was nothing to do other than set strict to true in tsconfig

How to test

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[kasperpeulen]

LGTM!

[jonniebigodes]

@kyletsang, one thing left to address as part of this initiative and the amazing work you did by helping us convert Storybook's packages to allow stricter TypeScript support. If you're ok with it, can you message me on our Discord server ( same username) so that I can follow up with you?

Hope you have a fantastic day.

Stay safe

[kyletsang]

Hi @jonniebigodes unfortunately, discord is not letting me join the server without entering a phone number, and I rather not do that. I've sent you a friend request so you can DM me