fix(l1_sender): use 1 confirmation for gateway sends, fix test reliability#1178

Artemka374-claude wants to merge 3 commits intomatter-labs:mainmatter-labs/zksync-os-server:mainfrom

Artemka374-claude:afo/increase-required-confirmationsArtemka374-claude/zksync-os-server:afo/increase-required-confirmationsCopy head branch name to clipboard