Builds done with `make` are inconsistent with `hack/install-ate.sh`

[bowei]

The builds done with make have LD-based version stamping.
hack/install-ate.sh does not currently support this. We should make everything consistent somehow for least surprise. We could:

• Use Go lang version stamping instead of LDFLAGS based one
• Funnel everything through one way of doing things and remove the alternatives.

#162 (review)

[thockin]

ko-build/ko#1675

ko-build/ko#1680