Incorrect octagonal pad shape in EAGLE import

Description

Octagonal pad shapes in EAGLE are regular, as opposed to only isogonal (i. e. are equilateral with 29.29% chamfer ratio and not e. g. 25% like often in their silkscreen or in Altium).

0.25 in pcbnew/plugins/eagle/eagle_plugin.cpp should probably be 0.2928932188 or 1 - M_SQRT1_2 (≈ 1 - √½).

See also https://www.eevblog.com/forum/manufacture/jlc-pcb-reorientation-of-octagonal-pads/msg3417092/#msg3417092

Steps to reproduce

1. Import EAGLE board in KiCad PCB Editor (e. g. https://oshpark.com/shared_projects/bVTbWS7s or any other EAGLE design with octagons from https://oshpark.com/shared_projects)
2. Octagonal pads don't look the same as in EAGLE:

bd8236cd7a9d9c6de87a5dd939ad2b50.brd

KiCad Version

Application: KiCad PCB Editor (64-bit)

Version: (6.0.4), release build

Libraries:
	wxWidgets 3.1.5

Platform: Windows 10 (build 19044), 64-bit edition, 64 bit, Little endian, wxMSW

	wxWidgets: 3.1.5 (wchar_t,wx containers)
	Boost: 1.76.0
	OCC: 7.6.0
	Curl: 7.78.0-DEV
	ngspice: 36
	Compiler: Visual C++ 1928 without C++ ABI

Build settings:
	KICAD_USE_OCC=ON
	KICAD_SPICE=ON