mockstore: add empty executor runtime information for unistore cop handler (#18640)
mockstore: add empty executor runtime information for unistore cop handler (#18640)

Signed-off-by: crazycs520 <174f850cd6ed76c2653f481397d398dd570f1f87@gmail.com>

Co-authored-by: Evan Zhou <a3ebb8cb1b322f2cd74f30be2eff396c8190df95@gmail.com>
pingcap/tidb,ngaut/tidb,c4pt0r/tidb,c4pt0r/tidb,EvilMcJerkface/tidb,kyle-wang/tidb,pingcap/tidb,pingcap/tidb,ngaut/tidb,ngaut/tidb,pingcap/tidb,coocood/tidb,c4pt0r/tidb,pingcap/tidb,ngaut/tidb,kyle-wang/tidb,kyle-wang/tidb,pingcap/tidb,c4pt0r/tidb,c4pt0r/tidb,kyle-wang/tidb,kyle-wang/tidb,EvilMcJerkface/tidb,c4pt0r/tidb,XuHuaiyu/tidb,coocood/tidb,kyle-wang/tidb,ngaut/tidb,ngaut/tidb,XuHuaiyu/tidb