deps: remove the unused 'animejs' dependency

[tbouffard]

The 'happy path' use custom JavaScript and CSS directly implemented in the application.

Notes

This doesn't change the size of the final bundle, but this prevents to download extra resources from npm.

[github-actions[bot]]

:recycle: PR Preview f86e4f2f8cf5ab2b6cab495c99fac4bcb98fcfdd has been successfully destroyed since this PR has been closed.

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