Fix: Correct search window calculation in ApplyXMLMixin

[pyob-bot]

Summary of Changes

This PR updates the loop range calculation in ApplyXMLMixin to use the length of the original search_lines list rather than search_lines_stripped. This ensures that the search window correctly accounts for the full block of code being replaced, preventing potential index errors or incorrect matching behavior.

Technical Impact

• Correctness: Aligns the iteration range with the actual number of lines being searched, ensuring the replacement logic operates on the intended scope.
• Stability: Prevents off-by-one errors during the code replacement process, leading to more reliable XML-based code transformations.