### 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)

v |= ct << 4;
				}
				if (i * 2 + 1 < script_key.length()) {
					char32_t ct = script_key[i * 2 + 1];
					if (is_digit(ct)) {
						ct = ct - '0';
					} else if (ct >= 'a' && ct <= 'f') {
						ct = 10 + ct - 'a';
					}
					v |= ct;
				}
				key.write[i] = v;
			}
		}
		fae.instantiate();
		if (fae.is_null()) {
			add_message(EXPORT_MESSAGE_ERROR, TTR("Save PCK"), TTR("Can't create encrypted file."));
			return ERR_CANT_CREATE;
		}
		err = fae->open_and_parse(f, key, FileAccessEncrypted::MODE_WRITE_AES256, false);
		if (err != OK) {
			add_message(EXPORT_MESSAGE_ERROR, TTR("Save PCK"), TTR("Can't open encrypted file to write."));
			return ERR_CANT_CREATE;
		}
		fhead = fae;
	}
	for (int i = 0; i < pd.file_ofs.size(); i++) {
		uint32_t string_len = pd.file_ofs[i].path_utf8.length();
		uint32_t pad = _get_pad(4, string_len);
		fhead->store_32(string_len + pad);