fix(ci): Clone repo with higher depth to fix codecov problems (#24211)
I have had a problem where Codecov either shows too much difference
between my PR and master, or no diff at all. Both states have happened
within the same PR as Codecov processed new webhooks from GitHub, and in
both cases merge commits were involved. With Codecov support I have
found that their uploader throws this particular error message, and
so let's try giving the uploader more commits so maybe next time it
determines the parent commits correctly (?).