Enable ESLint no-useless-escape (#23311)

.eslintrc.js

...ascript/mastodon/actions/push_notifications/registerer.js

app/javascript/mastodon/components/status.js

...astodon/features/account_gallery/components/media_item.js

...mastodon/features/compose/containers/warning_container.js

app/javascript/mastodon/features/compose/util/counter.js

app/javascript/mastodon/features/emoji/emoji_utils.js

...don/features/follow_recommendations/components/account.js

...mastodon/features/picture_in_picture/components/footer.js

...pt/mastodon/features/status/components/detailed_status.js

...javascript/mastodon/features/ui/components/boost_modal.js

config/webpack/shared.js