dashboard, env/linux-arm64/aws: update EC2 ami search query

This change updates which source ami is used as a base for the
creation of the linux-arm64-aws builder. Packer will now search for
the latest version of the arm64 Debian image to use as the source ami.

For golang/go#36841

Change-Id: I036dbaf7ee65d4e7028cd6a0cdf6710bf898fdd2
Reviewed-on: https://go-review.googlesource.com/c/build/+/266697
Trust: Carlos Amedee <carlos@golang.org>
Run-TryBot: Carlos Amedee <carlos@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/dashboard/builders.go b/dashboard/builders.go
index 679fbb1..8f1026c 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -520,7 +520,7 @@
 	},
 	"host-linux-arm64-aws": &HostConfig{
 		Notes:           "Debian Buster, EC2 arm64 instance. See x/build/env/linux-arm64/aws",
-		VMImage:         "ami-06f66c749c71b2511",
+		VMImage:         "ami-03089323a1d38e652",
 		ContainerImage:  "gobuilder-arm64-aws:latest",
 		machineType:     "m6g.xlarge",
 		isEC2:           true,