CON-9202 update Go to 1.20 and dependencies

Updated Go version to 1.20

Ran

go get -d github.com/digitalocean/godo@v1.99.0
go get -d golang.org/x/oauth2 v0.8.0
go get -d github.com/onsi/gomega@v1.27.7
go get -d k8s.io/api@v0.27.2
go get -d k8s.io/apimachinery@v0.27.2
go get -d k8s.io/client-go@v0.27.2
go get -d k8s.io/utils@v0.0.0-20230505201702-9f6742963106
go get -d sigs.k8s.io/controller-runtime@v0.15.0

go mod tidy 
go mod vendor
make test

IMG_TAG=v0.1.7 make release-manifests

digitalocean / do-operator

CON-9202 update Go to 1.20 and dependencies #42