Ensure CSS `.dark` rule selectors are applied (#7355)
* fix ignored dark rules
* add changeset
* add changeset
* tweak
* test threshold
* test threshold again
* remove threshold and fix story
* test
* story tweak
* story test
* separate undo/redo from large interaction story
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Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>