[Corn Flakes] Ruby fix flaky test: ensure generate_random_even_number returns even numbers

[Copilot]

RandomMathOperations#generate_random_even_number in Ruby was intermittently returning odd values, causing persistent flakiness in RandomMathOperations#generate_random_even_number returns an even number. This PR removes the odd-number injection path so the method is deterministically even within the expected range.

• Root-cause fix (Ruby)

  • Updated ruby/lib/random_math_operations.rb to generate even values directly from a bounded integer range and scaling by 2.
  • Removed the probabilistic +1 branch that occasionally produced odd results.

• Behavior preserved

  • Output range remains 0..100.
  • Method continues to use the class RNG (@rng) and existing interface.

def generate_random_even_number
  @rng.rand(0..50) * 2
end