### 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)

ERR_FAIL_COND_MSG(string_flags & UTF8_FLAG, "Unimplemented, can't read UTF-8 string table.");
					if (string_flags & UTF8_FLAG) {
					} else {
						uint32_t len = decode_uint16(&p_manifest[string_at]);
						Vector<char32_t> ucstring;
						ucstring.resize(len + 1);
						for (uint32_t j = 0; j < len; j++) {
							uint16_t c = decode_uint16(&p_manifest[string_at + 2 + 2 * j]);
							ucstring.write[j] = c;
						}
						string_end = MAX(string_at + 2 + 2 * len, string_end);
						ucstring.write[len] = 0;
						string_table.write[i] = ucstring.ptr();
					}
				}
				for (uint32_t i = string_end; i < (ofs + size); i++) {
					stable_extra.push_back(p_manifest[i]);
				}
				string_table_ends = ofs + size;
			} break;
			case CHUNK_XML_START_TAG: {
				int iofs = ofs + 8;
				uint32_t name = decode_uint32(&p_manifest[iofs + 12]);
				String tname = string_table[name];
				uint32_t attrcount = decode_uint32(&p_manifest[iofs + 20]);
				iofs += 28;
				for (uint32_t i = 0; i < attrcount; i++) {
					uint32_t attr_nspace = decode_uint32(&p_manifest[iofs]);
					uint32_t attr_name = decode_uint32(&p_manifest[iofs + 4]);
					uint32_t attr_value = decode_uint32(&p_manifest[iofs + 8]);