update dart-sass

[agentschmitt]

update to latest sass version will require some more work
see https://sass-lang.com/documentation/breaking-changes/

• deprecation of import https://sass-lang.com/blog/import-is-deprecated/
• deprecation of color functions like light, darken
• deprecation of js api

in addition we import sass from another package that also receives no updates
@recogito/recogito-client-core/themes/default/theme.scss'
so we may need to fork and update this package too