Use golang 1.20.5

Author: miguno

Dockerfile

@@ -4,7 +4,7 @@
 # (https://docs.docker.com/build/building/multi-stage/)
 
 # Stage 1 (to create a "build" image, ~850MB)
-FROM golang:1.19.5 AS builder
+FROM golang:1.20.5 AS builder
 # smoke test to verify if golang is available
 RUN go version