fix(coderd): use stable sorting for insights and improve test coverage (#9250)

Fixes #9213

coderd/coderd_test.go

@@ -2,6 +2,7 @@ package coderd_test
 
 import (
 	"context"
+	"flag"
 	"io"
 	"net/http"
 	"net/netip"
@@ -23,6 +24,9 @@ import (
 	"github.com/coder/coder/v2/testutil"
 )
 
+// updateGoldenFiles is a flag that can be set to update golden files.
+var updateGoldenFiles = flag.Bool("update", false, "Update golden files")
+
 func TestMain(m *testing.M) {
 	goleak.VerifyTestMain(m)
 }