planner: fix index merge reader may lost enforced prop sort when table plan is pure (#49844)#49888

Merged

ti-chi-bot[bot] merged 4 commits intopingcap:release-6.5from ti-chi-bot:cherry-pick-49844-to-release-6.5

Jan 24, 2024

+35-2

Commits on Dec 28, 2023

This is an automated cherry-pick of pingcap#49844

AilinKid
authored and
ti-chi-bot
committed

Commits on Jan 23, 2024