Supply correct return type for `sentryVitePlugin`

[Lutymane]

The factory function actually returns an array of plugins which caused issues with plugin management with an expectation it returns a single plugin. It should be noted either in docs, or properly typed to avoid issues for other users.

sentry-javascript-bundler-plugins/packages/vite-plugin/src/index.ts

Line 77 in 9c56454

export const sentryVitePlugin: (options?: Options) => any = sentryUnplugin.vite;

[chargome]

Hey @Lutymane, thanks for writing in – we'll have a look!