fix: clean up injected styles to prevent background persisting after errors (#1363)#1917

AbdullahShafqat-OG wants to merge 2 commits intosveltejs:mainsveltejs/svelte.dev:mainfrom

AbdullahShafqat-OG:persistent-background-after-errorsAbdullahShafqat-OG/svelte.dev:persistent-background-after-errorsCopy head branch name to clipboard