gitea/burnin-dummy/build.sh: bash equivalent of build.ps1 (sleep 30,
writes dist/build-info.txt). Needed because powershell is not present
on LinuxBuild2404 template.
scripts/Start-BurnInTest-Linux.ps1: burn-in wrapper for LinuxBuild2404
template (SnapshotName=BaseClean-Linux, GuestOS=Linux,
BuildCommand='bash build.sh'). Mirrors Start-BurnInTest.ps1.