test: enable parallel execution for MultigresCluster controller tests

Adds `t.Parallel()` to `TestMultigresClusterReconciler_Reconcile` and its subtests, as well as other unit tests in the MultigresCluster controller test suite.

This allows independent test cases to run concurrently, reducing the overall execution time of the test suite.

Author: fernando-villalba

pkg/cluster-handler/controller/multigrescluster/multigrescluster_controller_test.go

@@ -27,6 +27,8 @@ import (
 )
 
 func TestMultigresClusterReconciler_Reconcile(t *testing.T) {
+	t.Parallel()
+
 	scheme := runtime.NewScheme()
 	_ = multigresv1alpha1.AddToScheme(scheme)
 	_ = appsv1.AddToScheme(scheme)
@@ -1004,6 +1006,8 @@ func TestMultigresClusterReconciler_Reconcile(t *testing.T) {
 
 	for name, tc := range tests {
 		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
 			clientBuilder := fake.NewClientBuilder().
 				WithScheme(scheme).
 				WithObjects(tc.existingObjects...).
@@ -1061,6 +1065,8 @@ func TestMultigresClusterReconciler_Reconcile(t *testing.T) {
 }
 
 func TestSetupWithManager_Coverage(t *testing.T) {
+	t.Parallel()
+
 	defer func() {
 		if r := recover(); r != nil {
 			// Expected panic
@@ -1071,7 +1077,11 @@ func TestSetupWithManager_Coverage(t *testing.T) {
 }
 
 func TestTemplateLogic_Unit(t *testing.T) {
+	t.Parallel()
+
 	t.Run("MergeCellConfig", func(t *testing.T) {
+		t.Parallel()
+
 		tpl := &multigresv1alpha1.CellTemplate{
 			Spec: multigresv1alpha1.CellTemplateSpec{
 				MultiGateway: &multigresv1alpha1.StatelessSpec{
@@ -1155,6 +1165,8 @@ func TestTemplateLogic_Unit(t *testing.T) {
 	})
 
 	t.Run("MergeShardConfig", func(t *testing.T) {
+		t.Parallel()
+
 		tpl := &multigresv1alpha1.ShardTemplate{
 			Spec: multigresv1alpha1.ShardTemplateSpec{
 				MultiOrch: &multigresv1alpha1.MultiOrchSpec{
@@ -1233,6 +1245,8 @@ func TestTemplateLogic_Unit(t *testing.T) {
 	})
 
 	t.Run("ResolveGlobalTopo", func(t *testing.T) {
+		t.Parallel()
+
 		spec := &multigresv1alpha1.GlobalTopoServerSpec{TemplateRef: "t1"}
 		core := &multigresv1alpha1.CoreTemplate{
 			Spec: multigresv1alpha1.CoreTemplateSpec{
@@ -1258,6 +1272,8 @@ func TestTemplateLogic_Unit(t *testing.T) {
 	})
 
 	t.Run("ResolveMultiAdmin", func(t *testing.T) {
+		t.Parallel()
+
 		spec := &multigresv1alpha1.MultiAdminConfig{TemplateRef: "t1"}
 		core := &multigresv1alpha1.CoreTemplate{
 			Spec: multigresv1alpha1.CoreTemplateSpec{