bazel: Use rules_pkg-0.2.5
bazel: Use rules_pkg-0.2.5

It seems that 0.2.6 is not officially released yet.

dreal/dreal4,dreal/dreal4,dreal/dreal4,soonho-tri/dreal4,dreal/dreal4,soonho-tri/dreal4,soonho-tri/dreal4,soonho-tri/dreal4