* optimize knowhere unittest
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* code clean
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* optimize knowhere util
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* fix clang-format
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* update changelog
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* fix unittest build error
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>

* retry CI
Signed-off-by: Nyudong.cai <yudong.cai@zilliz.com>
Co-authored-by: NJin Hai <hai.jin@zilliz.com>