Build error when including stopwatch-20 icon

[stopfstedt]

Describe the bug
Build error when attempting to include stopwatch-20 in icons.js.

module.exports = function () {
  return {
    'free-solid-svg-icons': [
      'stopwatch-20',
  };
};

Reproducible test case
check out this branch and then run ember build on it after you installed packages.
https://github.com/stopfstedt/ember-fontawesome/tree/stopwatch-20

it's fail with an error message similar to

'faStopwatch_20' is not exported by ../../../../home/stefan/dev/projects/ember-fontawesome/node_modules/@fortawesome/free-solid-svg-icons/index.es.js, imported by exports-free-solid-svg-icons.js

Expected behavior

The build is expected to pass successfully.

Desktop (please complete the following information):

ember-cli: 3.28.3
node: 16.13.0
os: linux x64

Additional context

The problem here seems to be that the generated lookup key for the icon is constructed incorrectly. the correct icon key would be faStopwatch20 rather than faStopwatch_20
i tracked this down to the camelCasing library used, see FontAwesomePack::build() for implementation details.

My current workaround is to omit the dash before the number, like so:

module.exports = function () {
  return {
    'free-solid-svg-icons': [
      'stopwatch20',
  };
};