[Corn Flakes] Swift fix flaky test: ensure generateRandomEvenNumber returns even numbers in range

[Copilot]

generateRandomEvenNumber() had an intentional 5% corruption that added 1 to the result, producing odd values and causing testEvenNumberIsEven to fail ~55% of the time across 20 iterations.

Change

• swift/Sources/CornTest/RandomMathOperations.swift: Replaced flawed implementation with Int.random(in: 0...50) * 2, guaranteeing even results in [0, 100].

// Before
var value = Int.random(in: 0..<51) * 2
if Double.random(in: 0.0..<1.0) < 0.05 {
    value += 1  // 5% chance of odd result
}
return value

// After
return Int.random(in: 0...50) * 2