JS sourceMappingURL is wrong

[armanbilge]

Version(s)
0.1.11

Describe the bug
The sourceMappingURL doesn't match the name of the sourcemap.

To Reproduce

//> using platform "js"
//> using jsEmitSourceMaps true

@main def whatever = ()

$ scala-cli --version
0.1.11
$ scala-cli package bug.scala 
Compiling project (Scala 3.1.3, Scala.js)
Compiled project (Scala 3.1.3, Scala.js)
Emitted js source maps to: /workspace/sandbox/whatever.js.map
Wrote /workspace/sandbox/whatever.js, run it with
  node ./whatever.js
gitpod /workspace/sandbox (main) $ ls
bug.scala  README.md  whatever.js  whatever.js.map
$ tail -n 1 whatever.js
//# sourceMappingURL=main.js.map

Expected behaviour
The sourceMappingURL should match the name of the sourcemap.