In https://github.com/shopify/ruby-style-guide#syntax we say:

omit parentheses when the invocation is single-line and the method [...] is a class method call with implicit receiver.

But currently this isn't enforced by RuboCop.

The relevant cop is probably https://www.rubydoc.info/gems/rubocop/1.43.0/RuboCop/Cop/Style/MethodCallWithArgsParentheses