Merge branch 'renovate/golang-1.x' into 'master'

Update golang Docker tag to v1.18

See merge request !3

Dockerfile

-FROM golang:1.16 as build
+FROM golang:1.18 as build
 ADD . /src
 RUN cd /src && go build -tags netgo -o service-prober ./cmd/service-prober && strip service-prober