Don't export react with cdn bundle

[acao]

we don't need this line, because the CDN example already shows importing React at React global umd namespace, so React is available without bundling it with graphiql/graphiql.min .js

graphiql/packages/graphiql/src/cdn.ts

Line 47 in 4e92739

GraphiQL.React = GraphiQLReact;

this will require tweaking the plugin vite configs as well which are configured for this