qtest timeouts on cross-i686-tci job

The qtest-ppc/boot-serial-test seems to sometimes time out on the cross-i686-tci job, eg:

 45/257 qemu:qtest+qtest-ppc / qtest-ppc/boot-serial-test                  TIMEOUT        180.20s   killed by signal 15 SIGTERM

https://gitlab.com/qemu-project/qemu/-/jobs/5890481086 is an example of it just scraping in under the wire at 180s.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information