removing unused flag for old desktop

src/Core/Constants.cs

@@ -202,7 +202,6 @@ public static class FeatureFlagKeys
     public const string PM9111ExtensionPersistAddEditForm = "pm-9111-extension-persist-add-edit-form";
     public const string SecurityTasks = "security-tasks";
     public const string CipherKeyEncryption = "cipher-key-encryption";
-    public const string DesktopCipherForms = "pm-18520-desktop-cipher-forms";
     public const string PM19941MigrateCipherDomainToSdk = "pm-19941-migrate-cipher-domain-to-sdk";
     public const string EndUserNotifications = "pm-10609-end-user-notifications";
     public const string PhishingDetection = "phishing-detection";