Open action is available in non-standalone editors via hotkey

Description

We are supposed to not allow Open actions when running editors non-standalone, as Open changes the project. We hide the action from the File menu, but using the hotkey Ctrl+O when running in project mode still results in the open dialog appearing, which can then corrupt the project state if you choose a new file to open.

KiCad Version

Application: KiCad x86_64 on x86_64

Version: 7.0.11~rc1-202402091247~a3eca13ad3~ubuntu22.04.1, release build

Libraries:
	wxWidgets 3.2.1
	FreeType 2.11.1
	HarfBuzz 6.0.0
	FontConfig 2.13.1

Platform: Ubuntu 22.04.3 LTS, 64 bit, Little endian, wxGTK, ubuntu, x11

	wxWidgets: 3.2.1 (wchar_t,wx containers) GTK+ 3.24
	Boost: 1.74.0
	OCC: 7.6.3
	Curl: 7.88.1
	ngspice: 42
	Compiler: GCC 11.4.0 with C++ ABI 1016

Build settings:
	KICAD_SPICE=ON

(also affects latest nightly)