Remove '@sentry/browser' webpack alias

What does this MR do and why?

This change removes the webpack alias for @sentry/browser that points to ~/sentry/sentry_browser_wrapper.js.

This change is aimed to reduce indirection and make it easier for users to debug Sentry calls.

Screenshots or screen recordings

NA

How to set up and validate locally

A green pipeline 💚

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #339335 (closed)