fix: Storybook does not respect BROWSER env var

[thtliife]

Storybook does not respect BROWSER env var if default browser is not chromium based.

Closes #21343

What I did

This commit adds a check for the environment variable, and passes it to the open package as an argument if the specified browser is not chromium based.

Changes are in code/lib/core-server/src/utils/open-in-browser.ts

How to test

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[thtliife]

erm, pull bot undid my changes? this no longer fixes anything

[tmeasday]

I've no idea what's going on here. I definitely didn't merge anything. And that commit (485fd3a) points to an apparently unrelated @shilman commit...

[shilman]

What is the "pull" bot? Seems buggy to me

[thtliife]

@shilman Haha. It’s a bot that I had forgotten I had installed in my sccount.
it’s supposed to keep forks up to date with their parent repos…
But it seemed to have been doing a git fetch —hard…
Needless to say it’s no longer installed in my account 🤪