eeschema: editing arcs moves the wrong anchor

Description

When you go to edit an arc in eeschema, instead of grabbing the dot you're clicking on, the next of the three dots starts getting dragged instead (like an off-by-one index error or something). If you let go and then grab a dot again, the correct one gets dragged. If you deselect or ctrl-z, the next attempt will grab the wrong dot again.

This one's been around for a bit, but I (and I presume everyone else) keeps forgetting to file an issue for it.

arc.mkv

Steps to reproduce

Make an arc
Deselect it
Click it
Try to adjust dots

KiCad Version

Application: KiCad Schematic Editor x86_64 on x86_64

Version: 8.0.3-89-g3c4a3822d7, release build

Libraries:
	wxWidgets 3.2.4
	FreeType 2.11.1
	HarfBuzz 2.7.4
	FontConfig 2.13.1
	libcurl/7.81.0 OpenSSL/3.0.2 zlib/1.2.11 brotli/1.0.9 zstd/1.4.8 libidn2/2.3.2 libpsl/0.21.0 (+libidn2/2.3.2) libssh/0.9.6/openssl/zlib nghttp2/1.43.0 librtmp/2.3 OpenLDAP/2.5.17

Platform: Ubuntu 22.04.4 LTS, 64 bit, Little endian, wxGTK, X11, xubuntu, x11
OpenGL: Intel, Mesa Intel(R) Graphics (RPL-P), 4.6 (Compatibility Profile) Mesa 23.2.1-1ubuntu3.1~22.04.2

Build Info:
	Date: Jun 21 2024 09:42:14
	wxWidgets: 3.2.4 (wchar_t,wx containers) GTK+ 3.24
	Boost: 1.74.0
	OCC: 7.6.3
	Curl: 7.81.0
	ngspice: 36
	Compiler: GCC 11.4.0 with C++ ABI 1016

Build settings: