Add setting to enable/disable using the Octopus Deploy GitHub App

+semver: minor

GitOrigin-RevId: 870d7282d70f4180ff1d9357d07eeab89be2129b

Author: geofflamrock

source/Octopus.Client.Tests/PublicSurfaceAreaFixture.ThePublicSurfaceAreaShouldNotRegress..NETCore.approved.txt

@@ -3238,6 +3238,7 @@ Octopus.Client.Model
     Boolean IsCommunityActionTemplatesEnabled { get; set; }
     Boolean IsCompositeDockerHubRegistryFeedEnabled { get; set; }
     Boolean IsConfigureFeedsWithLocalOrSmbPathsEnabled { get; set; }
+    Boolean IsGitHubAppEnabled { get; set; }
     Boolean IsHelpSidebarEnabled { get; set; }
     Boolean IsKubernetesCloudTargetDiscoveryEnabled { get; set; }
     Boolean IsNavigationVisualUpliftEnabled { get; set; }

source/Octopus.Server.Client/Model/FeaturesConfigurationResource.cs

@@ -41,6 +41,9 @@ public class FeaturesConfigurationResource : Resource
         [Writeable]
         public bool IsProjectsPageOnboardingEnabled { get; set; }
 
+        [Writeable]
+        public bool IsGitHubAppEnabled { get; set; }
+
         [Writeable]
         public string DefaultPowerShellEdition { get; set; }
     }