Add support for macOS, Linux and web builds

[TheOneWithTheBraid]

Now, as Flutter officially supports macOS, the web and Linux, it would be great to have them available for build too. Maybe Linux will be a bit difficult to implement (as builds run on macOS) but web and macOS should be quite easy to support.

[bitce]

Thanks for the feature request @TheOneWithTheBraid!

[TheOneWithTheBraid]

Is there any effort or any plan to support non-mobile builds?

[github-actions[bot]]

Hello there, I'm a bot. On behalf of the community I thank you for opening this issue.

To help our human contributors focus on the most relevant reports, I check up on old issues to see if they're still relevant. This issue has had no activity for 90 days, so I marked it as stale.

The community would appreciate if you could check if the issue still persists. If it isn't, please close it. If the issue persists, and you'd like to remove the stale label, you simply need to leave a comment. Your comment can be as simple as "still important to me".

If no comment left within 21 days, this issue will be closed.

[TheOneWithTheBraid]

Still important.

[mefiblogger]

Hello,

It's Mefi here from the Bitrise CoreSteps Team. Thanks for reaching out helping us and the mobile community to have a better experience with Bitrise steps. 💜

We started to have a broader review of all the open issues and PRs and we are continuously prioritizing these in our sprints.

We reviewed this issue and we found it to be a valid feature request. We are collecting new feature requests on our Discuss forum where you can upvote and discuss further details. As this one is on our current roadmap, I close the issue and we'll share an update once we released the new version of the step. Until then, feel free to create a feature request and share your thoughts on Discuss.

Happy building! 🚀