Stand-in for an altstoreio/AltStore GitHub release, so the SideInstaller
AltStore prototype (branch altstore-install) has a
release to point at.
Each release has one asset, AltStore.ipa, so SideInstaller can use
releases/latest/download/AltStore.ipa the same way it does for SideStore.
The IPA is AltStore 2.3 (build 70) with its old signing removed:
embedded.mobileprovision, _CodeSignature, Extensions/AltMarketplace.appex,
and the ALTDeviceID / ALTServerID Info.plist keys. SideInstaller re-signs it
and writes its own ALTDeviceID while installing.
This is AltStore's own build, hosted for testing only. It isn't an official AltStore release channel.