bump go to 1.21 (#26608)

Co-authored-by: Giteabot <teabot@gitea.io>

Dockerfile

@@ -1,5 +1,5 @@
 #Build stage
-FROM docker.io/library/golang:1.20-alpine3.18 AS build-env
+FROM docker.io/library/golang:1.21-alpine3.18 AS build-env
 
 ARG GOPROXY
 ENV GOPROXY ${GOPROXY:-direct}

Dockerfile.rootless

@@ -1,5 +1,5 @@
 #Build stage
-FROM docker.io/library/golang:1.20-alpine3.18 AS build-env
+FROM docker.io/library/golang:1.21-alpine3.18 AS build-env
 
 ARG GOPROXY
 ENV GOPROXY ${GOPROXY:-direct}

Makefile

@@ -23,7 +23,7 @@ SHASUM ?= shasum -a 256
 HAS_GO := $(shell hash $(GO) > /dev/null 2>&1 && echo yes)
 COMMA := ,
 
-XGO_VERSION := go-1.20.x
+XGO_VERSION := go-1.21.x
 
 AIR_PACKAGE ?= github.com/cosmtrek/air@v1.44.0
 EDITORCONFIG_CHECKER_PACKAGE ?= github.com/editorconfig-checker/editorconfig-checker/cmd/editorconfig-checker@2.7.0