tag: align showcase and documentation

[mfranzke]

          these most likely result out of that within DB Tag the DB Radio component is being used, whereas within the showcases like e.g. https://design-system.deutschebahn.com/core-web/review/feat-optimize-hover-data-inputs/components/data-display/tag/overview it's a native radio element:

https://github.com/db-ux-design-system/core-web/blob/feat-optimize-hover-data-inputs/packages/components/src/components/tag/tag.spec.tsx#L86-L105

Originally posted by @mfranzke in #4077 (comment)