Avoid parenthesis only cleanup in SimplifyConstantIfBranchExecution

[Bananeweizen]

What's changed?

Recognize when the recipe cannot optimize to a constant condition and return the if-condition as before all attempted optimizations.

What's your motivation?

Fixes #286.

Checklist

• [x] I've added unit tests to cover both positive and negative cases
• [x] I've read and applied the recipe conventions and best practices
• [x] I've used the IntelliJ IDEA auto-formatter on affected files