Xcode 2.4 Release was released on 17 Aug 2006 and requires macOS 10.4+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/xcode_2.4/xcode_2.4_8k1079_6936199.dmg.
Release notes are located at https://download.developer.apple.com/Developer_Tools/xcode_2.4/xcode_2.4_readme.pdf.