dashboard: remove TRY=mac and macos

These aliases are out of date. Based on Gerrit search, TRY=mac has never
been used, and TRY=macos has been used only once since it was added in
2019.

Change-Id: I88480ffb116f3bccfcdcdf6610cf3b94614c4549
Reviewed-on: https://go-review.googlesource.com/c/build/+/432858
Reviewed-by: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/cmd/coordinator/coordinator_test.go b/cmd/coordinator/coordinator_test.go
index 476b699..03eb485 100644
--- a/cmd/coordinator/coordinator_test.go
+++ b/cmd/coordinator/coordinator_test.go
@@ -331,7 +331,7 @@
 			},
 			{
 				Version: 2,
-				Message: "arm64, mac aix ",
+				Message: "arm64, darwin aix ",
 			},
 			{
 				Version: 1,
@@ -344,7 +344,7 @@
 	for _, bc := range slowBots {
 		got = append(got, bc.Name)
 	}
-	want := []string{"aix-ppc64", "darwin-amd64-10_14", "linux-arm64-aws"}
+	want := []string{"aix-ppc64", "darwin-amd64-12_0", "linux-arm64-aws"}
 	if !reflect.DeepEqual(got, want) {
 		t.Errorf("mismatch:\n got: %q\nwant: %q\n", got, want)
 	}
diff --git a/dashboard/builders.go b/dashboard/builders.go
index 5ed0e02..44665e2 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -69,8 +69,6 @@
 	"linux-s390x":          "linux-s390x-ibm",
 	"longtest":             "linux-amd64-longtest",
 	"loong64":              "linux-loong64-3a5000",
-	"mac":                  "darwin-amd64-10_14",
-	"macos":                "darwin-amd64-10_14",
 	"mips":                 "linux-mips-rtrk",
 	"mips64":               "linux-mips64-rtrk",
 	"mips64le":             "linux-mips64le-rtrk",