Fix Create load report.

Author: CalebRas

Shared/Samples/Create load report/CreateLoadReportView.Model.swift

@@ -187,6 +187,8 @@ extension CreateLoadReportView {
         /// - Precondition: `allowsCreateLoadReport`
         func createLoadReport() async {
             precondition(allowsCreateLoadReport)
+            allowsCreateLoadReport = false
+            defer { updateAllowsCreateLoadReport() }
 
             guard let phasesNetworkAttribute,
                   let initialExpression,