desktop-file-validate is missing support for version 1.5 of the specification

According to the docs the current version of the specification is 1.5

Version | Version of the Desktop Entry Specification that the desktop entry conforms with. Entries that confirm with this version of the specification should use 1.5. Note that the version field is not required to be present.

Yet when running desktop-file-validate against a .desktop file with Version=1.5 in it I get the following error:

$ cat ~/Downloads/bitwig-studio.desktop 
[Desktop Entry]
Version=1.5
Type=Application
Terminal=false
StartupNotify=true
Name=Bitwig Studio
Comment=Music Application
Exec="/usr/bin/bitwig-studio"
Categories=AudioVideo;Music;Audio;Sequencer;Midi;Mixer;Player;Recorder
MimeType=application/bitwig-clip;application/bitwig-device;application/bitwig-package;application/bitwig-preset;application/bitwig-project;application/bitwig-scene;application/bitwig-template
StartupWMClass="Bitwig Studio"
$ desktop-file-validate ~/Downloads/bitwig-studio.desktop
/home/simon/Downloads/bitwig-studio.desktop: error: value "1.5" for key "Version" in group "Desktop Entry" is not a known version