Ethereum Core Developers Fix Total Difficulty Removal Bug After Merge

Ethereum core developers fix totalDifficulty removal in post-merge blocks. Sally MacFarlane updates acceptance test fixtures for totalDifficulty removal. Remaining fixes by Sally MacFarlane for correct operation after The Merge. The changes ensure smooth transition from pre-Merge to post-Merge mode. TotalDifficulty field is now omitted in post-merge blocks as planned. No further action needed for this update, only wait for node sync.