Update Golang version and replace Alpine with Distroless

Dockerfile

@@ -1,4 +1,5 @@
-FROM golang:1.22-bookworm as build
+ARG GOLANG_VERSION=1.22.7
+FROM golang:${GOLANG_VERSION} AS build
 LABEL maintainer="githubexporter"
 
 ENV GO111MODULE=on
@@ -10,13 +11,9 @@ RUN go mod download \
     && go test ./... \
     && CGO_ENABLED=0 GOOS=linux go build -o /bin/main
 
-FROM alpine:3
+FROM gcr.io/distroless/static AS runtime
 
-RUN apk --no-cache add ca-certificates \
-     && addgroup exporter \
-     && adduser -S -G exporter exporter
 ADD VERSION .
-USER exporter
 COPY --from=build /bin/main /bin/main
 ENV LISTEN_PORT=9171
 EXPOSE 9171