`implicit_return` doesn't trigger for if/switch expressions

Bug Description

The implicit_return rule does not trigger in cases where an if or switch is used as the only expression in a function, and each branch consists of only a single return statement:

// This does not trigger a violation:
func test() -> String {
    if .random() {
        return "A"
    } else {
        return "B"
    }
}

Mention the command or other SwiftLint integration method that caused the issue. Include stack traces or command output.

$ swiftlint

Environment

• SwiftLint version: 0.59.1
• Xcode version: Xcode 16.4 (16F6)
• Installation method used: built from source
• Configuration file:

  enabled_rules:
    - implicit_return
  

• no nested configurations

Start by running swiftlint with the shown enabled_rules configuration against the example, then locate the implicit_return rule implementation and its tests. Confirm that the if/switch single-return cases are reported while existing behavior remains unchanged.