fix: Substrait serialization mishandles sliced map literals - #25543

neilconway wants to merge 2 commits into

fix: Substrait serialization mishandles sliced map literals#25543
neilconway wants to merge 2 commits into
apache:mainfrom
neilconway:neilc/fix-substrait-sliced-map-literal

fix: preserve sliced map literals in Substrait