Improved code by updating any interfaces

Change-Id: I9a2e630c37f3c427569f5bbd773978c2705dc08c
diff --git a/service/client_test.go b/service/client_test.go
index 3827b09..0009d71 100644
--- a/service/client_test.go
+++ b/service/client_test.go
@@ -164,7 +164,7 @@
 	})
 
 	t.Run("Error handling", func(t *testing.T) {
-		var result map[string]interface{}
+		var result map[string]any
 		err := client.GetJSON(ctx, "/error", &result)
 
 		assert.Error(t, err)
@@ -189,7 +189,7 @@
 		if r.URL.Path == "/token" {
 			// Mock token endpoint
 			w.Header().Set("Content-Type", "application/json")
-			json.NewEncoder(w).Encode(map[string]interface{}{
+			json.NewEncoder(w).Encode(map[string]any{
 				"access_token": "test-access-token",
 				"token_type":   "Bearer",
 				"expires_in":   3600,
@@ -232,7 +232,7 @@
 	ctx := context.Background()
 
 	t.Run("Unauthenticated request", func(t *testing.T) {
-		var result map[string]interface{}
+		var result map[string]any
 		err := client.GetJSON(ctx, "/", &result)
 
 		assert.Error(t, err)
@@ -251,7 +251,7 @@
 	})
 
 	t.Run("Authenticated request", func(t *testing.T) {
-		var result map[string]interface{}
+		var result map[string]any
 		err := client.GetJSON(ctx, "/", &result)
 		assert.NoError(t, err)