feat: Support godot 4 projects

[AntonioDell]

By using the github actions input use_godot_4, exports with godot 4 are now possible. There are some error outputs in the workflow log, but they do not seem to affect the resulting build.

You can check the builds in my repo:

• Godot 4 (I fixed the unexpected input warning after the build)
• Godot 3

[firebelley]

@AntonioDell this looks excellent, the contribution is definitely appreciated!

I want to get this merged but have a question before I do. Currently there is an editor_settings-3.tres file in the dist directory that is used for basic editor settings required for exports. Is there a new editor_settings file for Godot 4? I haven't yet tried out Godot 4, so I'm sure it's possible that the format hasn't changed. But would be great to get confirmation from you that there's no a different settings file we'll need to support. The fact that your builds succeeded seems to indicate that it works just fine, but again just want to make sure!

[AntonioDell]

That is a good point, I didn't even notice the settings file. I need some time to check this :)

[AntonioDell]

The location of the editor settings remains the same as in godot 3, as per documentation:

The format of the settings file is still the same, it may have some different keys (for a comprehensive list of options take a look at the official docs), but the key used in /dist/editor_setting-3.tres still exists and did not change.

Does that answer your questions?