`_export_file()` not called for GDScript files

[KoBeWi]

Tested versions

4.3 beta2

System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 31.0.15.4633) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

Issue description

Related to #67844
When I export my project _export_file() does not see GDScript files and they all get exported. It does not happen in a minimal project, I don't know what causes it.

Steps to reproduce

1. Open my project ;_;
2. Export ZIP
3. My export plugin should filter out some .gd files, but all are included in the zip

Minimal reproduction project (MRP)

I have maximal reproduction project.

[KoBeWi]

Ok so the reason why there was difference in my project and my test project is that the export plugin in the test project was named AAAAAAAAA. Apparently editor will process export plugins in alphabetical order and there is GDScriptExportPlugin that changes .gd files to .gdc. If you want to skip a GDScript file, you need to do so before its processed by that plugin.

My fix was appending the export plugin's name in my project with A. idk if it's something that should be documented or what.