simulation model editor: typing disabled in filename field

Description

Current behavior: It is possible to set cursor into filename field but nothing can't be typed in:

Expected behavior: user can type or paste anything he wants into this field

Steps to reproduce

1. Open dialog
2. Try to type something into File field.

KiCad Version

Application: KiCad Symbol Editor

Version: (6.99.0-4407-gd63eac9778), release build

Libraries:
	wxWidgets 3.0.5
	FreeType 2.11.1
	HarfBuzz 2.7.4
	FontConfig 2.13.1

Platform: Linux 5.15.0-48-generic x86_64, 64 bit, Little endian, wxGTK, cinnamon, x11

	wxWidgets: 3.0.5 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
	Boost: 1.74.0
	OCC: 7.5.1
	Curl: 7.81.0
	ngspice: 37+
	Compiler: GCC 11.3.0 with C++ ABI 1016

Build settings:
	KICAD_SPICE=ON