Only delete agent when not succesful (#13865)
Only delete agent when not succesful (#13865)

Spinup for this agent is unreliable (docker fails to start a lot).  Only delete when the build fails.
kyulee1/coreclr,wtgodbe/coreclr,parjong/coreclr,poizan42/coreclr,wtgodbe/coreclr,wateret/coreclr,botaberg/coreclr,ruben-ayrapetyan/coreclr,ruben-ayrapetyan/coreclr,dpodder/coreclr,mmitche/coreclr,kyulee1/coreclr,botaberg/coreclr,AlexGhiondea/coreclr,krk/coreclr,parjong/coreclr,poizan42/coreclr,dpodder/coreclr,krk/coreclr,AlexGhiondea/coreclr,wtgodbe/coreclr,poizan42/coreclr,botaberg/coreclr,JosephTremoulet/coreclr,yizhang82/coreclr,botaberg/coreclr,AlexGhiondea/coreclr,kyulee1/coreclr,hseok-oh/coreclr,parjong/coreclr,ruben-ayrapetyan/coreclr,hseok-oh/coreclr,poizan42/coreclr,JosephTremoulet/coreclr,kyulee1/coreclr,yizhang82/coreclr,krk/coreclr,rartemev/coreclr,wateret/coreclr,rartemev/coreclr,kyulee1/coreclr,yizhang82/coreclr,dpodder/coreclr,botaberg/coreclr,wtgodbe/coreclr,JosephTremoulet/coreclr,cshung/coreclr,rartemev/coreclr,wateret/coreclr,cshung/coreclr,poizan42/coreclr,AlexGhiondea/coreclr,yizhang82/coreclr,ruben-ayrapetyan/coreclr,mmitche/coreclr,wtgodbe/coreclr,JosephTremoulet/coreclr,kyulee1/coreclr,botaberg/coreclr,dpodder/coreclr,cshung/coreclr,wateret/coreclr,krk/coreclr,parjong/coreclr,wateret/coreclr,yizhang82/coreclr,AlexGhiondea/coreclr,hseok-oh/coreclr,dpodder/coreclr,hseok-oh/coreclr,poizan42/coreclr,JosephTremoulet/coreclr,rartemev/coreclr,cshung/coreclr,rartemev/coreclr,cshung/coreclr,hseok-oh/coreclr,ruben-ayrapetyan/coreclr,parjong/coreclr,mmitche/coreclr,mmitche/coreclr,JosephTremoulet/coreclr,parjong/coreclr,ruben-ayrapetyan/coreclr,wtgodbe/coreclr,wateret/coreclr,krk/coreclr,cshung/coreclr,hseok-oh/coreclr,krk/coreclr,dpodder/coreclr,rartemev/coreclr,AlexGhiondea/coreclr,mmitche/coreclr,yizhang82/coreclr,mmitche/coreclr