GH_DEBUG=api captures for cli/cli#14404
Three merges of the same repository from the same clone, gh 2.100.0,
prompt=disabled, non-interactive. The only thing changed between them is the
case of the owner segment in remote.origin.url. --delete-branch --merge was
passed every time, and gh exited 0 every time with no error printed.
"Automatically delete head branches" was off for the whole sequence, re-checked before arm C and after arm L2.