dashboard,env/freebsd: add 12.3-STABLE

With the XSAVE bug fix.

For golang/go#49967, golang/go#46272.

Change-Id: Ie0711ba83e4f15d26e6fe89e89c80b7c3ad2c23c
Reviewed-on: https://go-review.googlesource.com/c/build/+/375695
Trust: Heschi Kreinick <heschi@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/dashboard/builders_test.go b/dashboard/builders_test.go
index 5f8a860..2a38f14 100644
--- a/dashboard/builders_test.go
+++ b/dashboard/builders_test.go
@@ -93,6 +93,7 @@
 			want: []string{
 				"android-amd64-emu",
 				"freebsd-amd64-12_2",
+				"freebsd-amd64-12_3",
 				"js-wasm",
 				"linux-386",
 				"linux-amd64",
@@ -128,6 +129,7 @@
 			want: []string{
 				"android-amd64-emu",
 				"freebsd-amd64-12_2",
+				"freebsd-amd64-12_3",
 				"js-wasm",
 				"linux-386",
 				"linux-amd64",
@@ -163,6 +165,7 @@
 			want: []string{
 				"android-amd64-emu",
 				"freebsd-amd64-12_2",
+				"freebsd-amd64-12_3",
 				"js-wasm",
 				"linux-386",
 				"linux-amd64",
@@ -200,6 +203,7 @@
 			want: []string{
 				"android-amd64-emu",
 				"freebsd-amd64-12_2",
+				"freebsd-amd64-12_3",
 				"js-wasm",
 				"linux-386",
 				"linux-amd64",
@@ -247,6 +251,7 @@
 				"freebsd-386-13_0",
 				"freebsd-amd64-11_4",
 				"freebsd-amd64-12_2",
+				"freebsd-amd64-12_3",
 				"freebsd-amd64-13_0",
 				"linux-386",
 				"linux-amd64",