chore(type): clarifies optional type with explicit undefined

[aiktb]

I always use "exactOptionalPropertyTypes": true, in TypeScript, so authToken? string and authToken?: string | undefined; are not equivalent. In short, the former type will cause the following code to have a TypeScript error:

  vite: () => ({
    plugins: [
      sentryVitePlugin({
        authToken: undefined,
      }),
    ],
  }),

Like this:

[Copilot]

Pull Request Overview

This PR clarifies the type definition for the authToken property by making the undefined type explicit in the union type.

• Updated the authToken property type from optional to explicitly include undefined in the union type

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[aiktb]

Why is the test failing? It doesn't seem to be related to my commit.