Inkscape build toolset v0.61

Most notable changes in this release are

• fix toolset installation for union-mount
• fix wheels archive being empty

build info

• workflow run release #70
• sha256 is 435caf43c11100ad2195735c10c2a85c49e92e8ac3ee99024d018096f611ab60
• important parameters

  SYS_MACOS_VER = 10.15.7
  SYS_SDK_VER = 10.13
  VERSION = 0.61
  VER_DIR = /Users/Shared/work/mibap-0.61
  WRK_DIR = /Users/Shared/work