stream-clone-test: simplify the case testing phases
There is only two important things in this test:
- the number of file we send, to show we picked the phase roots.
- the resulting phases, to show we did not modified them.
The rest are of the number are very fragile and consume a lot of time for little
value when adjusting formats, caches, and protocol.
# So GitLab doesn't think we're using tons of Perl
*.t -linguist-detectable