Remove v15 fallback for SAML SP apps

lib/web/apps.go

@@ -60,23 +60,7 @@ func (h *Handler) clusterAppsGet(w http.ResponseWriter, r *http.Request, p httpr
 
 	page, err := apiclient.GetResourcePage[types.AppServerOrSAMLIdPServiceProvider](r.Context(), clt, req)
 	if err != nil {
-		// If the error returned is due to types.KindAppOrSAMLIdPServiceProvider being unsupported, then fallback to attempting to just fetch types.AppServers.
-		// This is for backwards compatibility with leaf clusters that don't support this new type yet.
-		// DELETE IN 15.0
-		if trace.IsNotImplemented(err) {
-			req, err = convertListResourcesRequest(r, types.KindAppServer)
-			if err != nil {
-				return nil, trace.Wrap(err)
-			}
-			appServerPage, err := apiclient.GetResourcePage[types.AppServer](r.Context(), clt, req)
-			if err != nil {
-				return nil, trace.Wrap(err)
-			}
-			// Convert the ResourcePage returned containing AppServers to a ResourcePage containing AppServerOrSAMLIdPServiceProviders.
-			page = appServerOrSPPageFromAppServerPage(appServerPage)
-		} else {
-			return nil, trace.Wrap(err)
-		}
+		return nil, trace.Wrap(err)
 	}
 
 	userGroups, err := apiclient.GetAllResources[types.UserGroup](r.Context(), clt, &proto.ListResourcesRequest{
@@ -449,28 +433,3 @@ func (h *Handler) proxyDNSNames() (dnsNames []string) {
 	}
 	return dnsNames
 }
-
-// appServerOrSPPageFromAppServerPage converts a ResourcePage containing AppServers to a ResourcePage containing AppServerOrSAMLIdPServiceProviders.
-// DELETE IN 15.0
-//
-//nolint:staticcheck // SA1019. To be deleted along with the API in 16.0.
-func appServerOrSPPageFromAppServerPage(appServerPage apiclient.ResourcePage[types.AppServer]) apiclient.ResourcePage[types.AppServerOrSAMLIdPServiceProvider] {
-	resources := make([]types.AppServerOrSAMLIdPServiceProvider, len(appServerPage.Resources))
-
-	for i, appServer := range appServerPage.Resources {
-		// Create AppServerOrSAMLIdPServiceProvider object from appServer.
-		appServerOrSP := &types.AppServerOrSAMLIdPServiceProviderV1{
-			Resource: &types.AppServerOrSAMLIdPServiceProviderV1_AppServer{
-				AppServer: appServer.(*types.AppServerV3),
-			},
-		}
-
-		resources[i] = appServerOrSP
-	}
-
-	return apiclient.ResourcePage[types.AppServerOrSAMLIdPServiceProvider]{
-		Resources: resources,
-		Total:     appServerPage.Total,
-		NextKey:   appServerPage.NextKey,
-	}
-}