Some test snapshots cannot be updated

[ehmicky]

ava -u refuses to update the snapshots of some test files:

$ ava -u packages/build/tests/log/tests.js 
Could not update snapshots for the following test files:
⚠ packages/build/tests/log/tests.js

The problem is due to test.skip() being incompatible with ava -u: avajs/ava#2634
This was fixed in this PR: avajs/ava#2685
However the PR will be released with Ava v4, which is still in alpha.

In the meantime, we should comment those tests out instead of using test.skip().

[ehmicky]

Fixed at #3616