update buildbot repo

Ran the following commands
from $SKIA_ROOT
go get go.skia.org/infra@e5c4a9cfc497134f1241501b42277d40f3f02340
make -C infra/bots train

Change-Id: Id00ebbe564edfe9024e3291ff0726e92bc05965f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/338217
Commit-Queue: Nathaniel Nifong <nifong@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
3 files changed