Document Vite workaround for browser build

[curran]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

resolves #5208

Description

Adds a brief note about the workaround required in Vite to support the browser build to the v4 migration guide.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
rollup	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Oct 17, 2023 6:28pm

[codecov]

Codecov Report

Merging #5209 (5c755d8) into master (51c974d) will not change coverage.
Report is 1 commits behind head on master.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #5209   +/-   ##
=======================================
  Coverage   98.82%   98.82%           
=======================================
  Files         231      231           
  Lines        8849     8849           
  Branches     2314     2314           
=======================================
  Hits         8745     8745           
  Misses         43       43           
  Partials       61       61           

[lukastaegert]

Hi, thanks for figuring that out. I knew it "should work" because the REPL uses the browser build (and is using Vite), but of course it avoids issues with npm run dev simply because that one runs against Rollup sources and not the compiled browser bundle.

[github-actions]

This PR has been released as part of rollup@4.1.5. You can test it via npm install rollup.