test: modify test case

test: adjust check valgrind.sh

fix:  index mem leak

fix(query): copy the column that will not output.

refactor(sync): snapshot strategy

* chore: update taos-tools

for 3.0

* chore: update taos-tools

* chore: update taos-tools
Co-authored-by: Nzhaoyanggh <yzhao@taosdata.com>

fix(query): top/bottom parameter check failure on int type

test: adjust valgrind case

fix(query): stddev function support unsigned data types

TD-16994

test：update testcase for function timediff() and timetruncate()

test: adjust valgrind cases

enh: refactor scheduler code

os: add file auto del func