### Tested versions

Godot Engine v4.2.stable.official.46dc27791

### System information

Windows 10

### Issue description

When exporting to web, Godot fails with this error in the console:

> scene/main/window.cpp:884 - Attempting to make child window exclusive, but the parent window already has another exclusive child. This window: /root/@<!-- -->EditorNode@<!-- -->17120/@<!-- -->Panel@<!-- -->13/@<!-- -->ProjectExportDialog@<!-- -->559/@<!-- -->VBoxContainer@<!-- -->137/@<!-- -->AcceptDialog@<!-- -->411, parent window: /root/@<!-- -->EditorNode@<!-- -->17120/@<!-- -->Panel@<!-- -->13/@<!-- -->ProjectExportDialog@<!-- -->559, current exclusive child window: /root/@<!-- -->EditorNode@<!-- -->17120/@<!-- -->Panel@<!-- -->13/@<!-- -->ProjectExportDialog@<!-- -->559/@<!-- -->ProgressDialog@<!-- -->17444

![a](https://github.com/godotengine/godot/assets/2000051/bf9d22aa-d3fe-4e11-bff6-c387e740fe90)

This happens for newly created empty projects.


### Steps to reproduce

1. Open the attached project (or create a new project).
2. Project->Export->Export All
3. Observe the console error.  No output files are generated.


### Minimal reproduction project (MRP)

[export_test.zip](https://github.com/godotengine/godot/files/13574810/export_test.zip)

fhead->store_buffer((const uint8_t *)pd.file_ofs[i].path_utf8.get_data(), string_len);
		for (uint32_t j = 0; j < pad; j++) {
			fhead->store_8(0);
		}
		fhead->store_64(pd.file_ofs[i].ofs);
		fhead->store_64(pd.file_ofs[i].size); 
		fhead->store_buffer(pd.file_ofs[i].md5.ptr(), 16); 
		uint32_t flags = 0;
		if (pd.file_ofs[i].encrypted) {
			flags |= PACK_FILE_ENCRYPTED;
		}
		fhead->store_32(flags);
	}
	if (fae.is_valid()) {
		fhead.unref();
		fae.unref();
	}
	int header_padding = _get_pad(PCK_PADDING, f->get_position());
	for (int i = 0; i < header_padding; i++) {
		f->store_8(0);
	}
	uint64_t file_base = f->get_position();
	f->seek(file_base_ofs);
	f->store_64(file_base); 
	f->seek(file_base);
	
	ftmp = FileAccess::open(tmppath, FileAccess::READ);
	if (ftmp.is_null()) {
		DirAccess::remove_file_or_error(tmppath);
		add_message(EXPORT_MESSAGE_ERROR, TTR("Save PCK"), vformat(TTR("Can't open file to read from path \"%s\"."), tmppath));