Update golang Docker tag

renovate[bot] · web-flow · commit df261335f027 · 2023-07-09T11:28:11.000Z
diff --git a/.tool-versions b/.tool-versions
@@ -1 +1 @@
-golang 1.18
+golang 1.20.5
diff --git a/Dockerfile b/Dockerfile
@@ -2,7 +2,7 @@
 ###############################
 # Build the doctree Go binary #
 ###############################
-FROM golang:1.18-alpine as builder
+FROM golang:1.20-alpine@sha256:fd9d9d7194ec40a9a6ae89fcaef3e47c47de7746dd5848ab5343695dbbd09f8c as builder
 
 RUN apk add --no-cache git build-base
 COPY . /doctree
