This reverts commit e00fb2bdc2090e9cabeb1eb35a2672a882cc96e9.

# Conflicts:
#	.rubocop.yml
#	.rubocop_todo.yml
#	lib/gitlab/ci/config/entry/global.rb
#	lib/gitlab/ci/config/entry/jobs.rb
#	spec/lib/gitlab/ci/config/entry/factory_spec.rb
#	spec/lib/gitlab/ci/config/entry/global_spec.rb
#	spec/lib/gitlab/ci/config/entry/job_spec.rb
#	spec/lib/gitlab/ci/status/build/factory_spec.rb
#	spec/lib/gitlab/incoming_email_spec.rb

This reverts commit cb10b725c8929b8b4460f89c9d96c773af39ba6b.

Closes #26921

They were Rails' default and are unnecessarily overridden.

Signed-off-by: David Wagner <david@marvid.fr>

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4093#note_12563922

For clarification and consistency

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4093/diffs#note_12501400

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4641#note_12444891

Feedback from:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4093#note_12413950

Feedback from:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4093#note_12321267

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4093#note_12321240

This also moves tests from build_spec.rb to runner_spec.rb

Without that, Rails would complain:

> bind message supplies 5 parameters, but prepared statement "a4" requires 4

However without this workaround it would still work in Rails console,
so I still think this is a Rails bug somewhere.

for a particular project.

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

Favor `unless` over `if` for negative conditions
(or control flow ||).

See #17478