Fix Ruby 2.7 deprecation warnings in snippet_input_action_spec.rb

What does this MR do?

In Ruby 3.0, positional arguments and keyword arguments will be separated. Ruby 2.7 will warn for behaviors that will change in Ruby 3.0. In most cases, you can avoid the incompatibility by adding the double splat operator. It explicitly specifies passing keyword arguments instead of a Hash object.

Part of #257438 (closed)

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines
• Style guides
• Separation of EE specific content