Do not bless by default in ui tests

[Alexendoo]

This restores the default behaviour to check the .stderr, it was changed in #11239 to bless by default in cargo test (unless in github actions), but check by default in cargo uitest which is fairly confusing

It also meant cargo uitest -F internal no longer worked

--bless prevents the use of Args::test but we can look at reintegrating with that after @oli-obk's vacation

r? @flip1995

changelog: none

[flip1995]

@bors r+

Thanks! I also was surprised by the bless-by-default change, but didn't want to block the bitrotty PR on that. Agreed that the check-by-default behavior feels more natural.

[bors]

📌 Commit 3ac06a1 has been approved by flip1995

It is now in the queue for this repository.

[bors]

⌛ Testing commit 3ac06a1 with merge 83afad4...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: flip1995
Pushing 83afad4 to master...