backport of commit aad932e (#19716)

Co-authored-by: Seth Hoenig <shoenig@duck.com>

.changelog/19709.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+build: update to go 1.21.6
+```

.go-version

@@ -1 +1 @@
-1.21.5
+1.21.6

contributing/README.md

@@ -30,7 +30,7 @@ A development environment is supplied via Vagrant to make getting started easier
 
 Developing without Vagrant
 ---
-1. Install [Go 1.21.5+](https://golang.org/) *(Note: `gcc-go` is not supported)*
+1. Install [Go 1.21.6+](https://golang.org/) *(Note: `gcc-go` is not supported)*
 1. Clone this repo
    ```sh
    $ git clone https://github.com/hashicorp/nomad.git

scripts/linux-priv-go.sh

@@ -21,7 +21,7 @@ case $(arch) in
 esac
 
 function install_go() {
-	local go_version="1.21.5"
+	local go_version="1.21.6"
 	local download="https://storage.googleapis.com/golang/go${go_version}.linux-${ARCH}.tar.gz"
 
 	if go version 2>&1 | grep -q "${go_version}"; then

scripts/release/mac-remote-build

@@ -56,7 +56,7 @@ REPO_PATH="${TMP_WORKSPACE}/gopath/src/github.com/hashicorp/nomad"
 mkdir -p "${TMP_WORKSPACE}/tmp"
 
 install_go() {
-  local go_version="1.21.5"
+  local go_version="1.21.6"
   local download=
 
   download="https://storage.googleapis.com/golang/go${go_version}.darwin-amd64.tar.gz"