[WIP]: add v8.5.4 release notes#21000

Draft

qiancai wants to merge 19 commits intopingcap:masterfrom

qiancai:v8.5.4-rn

Commits on Oct 15, 2025

Commits on Oct 16, 2025

add tiflash improvements and bug bixes

qiancai
and
JaySon-Huang
authored

Commits on Oct 20, 2025

add transaction bug fixes

qiancai
and
ekexium
authored
add bug fixes for execution

qiancai
and
gengliqi
authored
pd dc
bufferflies
committed

Commits on Oct 22, 2025

Commits on Oct 24, 2025