app/appengine: remove the security branches from the build dashboard

They're causing unnecessary work and clutter on the build.golang.org page.

Fixes golang/go#29513

Change-Id: Ieb9bbe4caf0041dd2a2f0e34b4d52a283de56224
Reviewed-on: https://go-review.googlesource.com/c/157817
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

app/appengine/dash.go

@@ -204,10 +204,12 @@ var gccgoDash = &Dashboard{
 // This also prevents the builder infrastructure
 // from testing sub-repos against these branches.
 var hiddenBranches = map[string]bool{
-	"release-branch.go1.4": true,
-	"release-branch.go1.5": true,
-	"release-branch.go1.6": true,
-	"release-branch.go1.7": true,
-	"release-branch.go1.8": true,
-	"release-branch.go1.9": true,
+	"release-branch.go1.4":           true,
+	"release-branch.go1.5":           true,
+	"release-branch.go1.6":           true,
+	"release-branch.go1.7":           true,
+	"release-branch.go1.8":           true,
+	"release-branch.go1.9":           true,
+	"release-branch.go1.10-security": true,
+	"release-branch.go1.11-security": true,
 }

app/appengine/ui.go

@@ -184,6 +184,10 @@ func listBranches(c context.Context) (branches []string) {
 		return
 	}
 	for _, c := range commits {
+		if strings.HasPrefix(c.Branch, "release-branch.go") &&
+			strings.HasSuffix(c.Branch, "-security") {
+			continue
+		}
 		branches = append(branches, c.Branch)
 	}
 	return