all: update Go versions in Dockerfiles

Now that the Go bootstrap version has been updated, the tip playground
deployment is failing. We need a better long-term fix, but for now just
bump the bootstrap version.

Also update the (very old) Go version in the sandbox Dockerfile.

Updates golang/go#69238

Change-Id: I14f1bc59904d8fd83cac0aca7efc2dc932a2ce64
Reviewed-on: https://go-review.googlesource.com/c/playground/+/610336
Reviewed-by: Tim King <taking@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

Dockerfile

diff --git a/Dockerfile b/Dockerfile
index d3f60ae..4d26bff 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,7 +10,7 @@
 
 # GO_VERSION is provided by Cloud Build, and is set to the latest
 # version of Go. See the configuration in the deploy directory.
-ARG GO_VERSION=go1.19
+ARG GO_VERSION=go1.22.6
 
 ############################################################################
 # Build Go at GO_VERSION, and build faketime standard library.
@@ -22,7 +22,7 @@
 
 ENV GOPATH /go
 ENV GOROOT_BOOTSTRAP=/usr/local/go-bootstrap
-ENV GO_BOOTSTRAP_VERSION go1.20.6
+ENV GO_BOOTSTRAP_VERSION go1.22.6
 ARG GO_VERSION
 ENV GO_VERSION ${GO_VERSION}
 

sandbox/Dockerfile

diff --git a/sandbox/Dockerfile b/sandbox/Dockerfile
index ffc3330..f084af4 100644
--- a/sandbox/Dockerfile
+++ b/sandbox/Dockerfile
@@ -4,7 +4,7 @@
 # environment so the play-sandbox server can connect to the host's
 # docker daemon, which has the gvisor "runsc" runtime available.
 
-FROM golang:1.18 AS build
+FROM golang:1.22 AS build
 
 COPY go.mod /go/src/playground/go.mod
 COPY go.sum /go/src/playground/go.sum