[BUG] Generated code includes "node:util" with target-env=browser

[rizo]

Opening this as a dedicated issue, since this has been preventing me from upgrading to the latest version.

I noticed a related issue. My js files contain references to node even when compiled for the browser target.

This only happens with the dev profile. With release, the issue is gone.

dune:

(executable
 (name test)
 (modes js)
 (js_of_ocaml
  (flags (:standard --target-env browser))
  (build_runtime_flags (:standard --target-env browser))))

Produces a js file with "node:util":

$ dune build tests/test.bc.js; cat _build/default/tests/test.bc.js | grep 'node:util'
    const util = require("node:util");

Versions

$ dune --version
3.20.2

$ dune exec -- js_of_ocaml --version
6.2.0  

If this is something new, happy to open a separate issue and help with investigation.

Originally posted by @rizo in #1809