Remove hard-requirement for react-18 so we can use icons (and by that the ds with react 19)

[LilithWittmann]

Could not resolve dependency:
npm error peer react@"^18.2.0" from @tokens-studio/icons-v2@0.0.2
npm error node_modules/@tokens-studio/icons-v2
npm error peer @tokens-studio/icons-v2@"0.0.2" from @tokens-studio/ui@3.1.0
npm error node_modules/@tokens-studio/ui
npm error @tokens-studio/ui@"^3.1.0" from the root project
npm error @tokens-studio/icons-v2@"^0.0.2" from the root project
npm error
npm error Conflicting peer dependency: react@18.3.1
npm error node_modules/react
npm error peer react@"^18.2.0" from @tokens-studio/icons-v2@0.0.2
npm error node_modules/@tokens-studio/icons-v2
npm error peer @tokens-studio/icons-v2@"0.0.2" from @tokens-studio/ui@3.1.0
npm error node_modules/@tokens-studio/ui
npm error @tokens-studio/ui@"^3.1.0" from the root project
npm error @tokens-studio/icons-v2@"^0.0.2" from the root project