A construction company foreman pleaded no contest to violating the state Labor Code in the case of a Stockton laborer who died when the walls of an unreinforced 13-foot-deep trench collapsed. Kenneth Gordo, 36, of Sparks, Nev., initially was charged with involuntary manslaughter, but the charge was dropped before he entered the plea at Tracy Municipal Court. Gordo had been in and out of the trench six times before it collapsed and suffocated Raymond Watkings, 50, last Sept. 6, at a $4.4-million sewer construction site in Tracy. The plea acknowledged the trench working conditions constituted a serious violation of the Labor Code because of the probability that death could result. Sentencing was set Aug. 11.