Update golang Docker tag

renovate[bot] · web-flow · commit 24b372fa36c2 · 2023-10-10T19:52:14.000Z
diff --git a/.tool-versions b/.tool-versions
@@ -1 +1 @@
-golang 1.18
+golang 1.21.3
diff --git a/Dockerfile b/Dockerfile
@@ -2,7 +2,7 @@
 ###############################
 # Build the doctree Go binary #
 ###############################
-FROM golang:1.18-alpine as builder
+FROM golang:1.21-alpine@sha256:b3360284c6dba9d8b33d8474ffdb07922c1d6c0057055b5d8ad9192320929f93 as builder
 
 RUN apk add --no-cache git build-base
 COPY . /doctree
