Fix Enumerable.sum deprecation warning
What does this MR do and why?
We currently have a large number of deprecation warning coming from the use of Enumerable.sum
Rails 7 has deprecated it's core extension version of Enumerable#sum
in favour of the native Ruby version that has been available since Ruby
2.4
See https://github.com/rails/rails/pull/42080
The version in Ruby requires an argument, essentially similar to
Enumerable#inject
. This will usually be a 'zero' value instance of
the types to be summed together.
A small change has been made to Gitlab::Ci::Reports::TestSuite#+(other)
to
ensure this change doesn't break existing behaviour.