Run sync ups tests with main serial executor (#3431)

* wip

* wip

Author: mbrandonw

Examples/SyncUps/SyncUpsTests/AppFeatureTests.swift

@@ -6,6 +6,8 @@ import Testing
 
 @MainActor
 struct AppFeatureTests {
+  init() { uncheckedUseMainSerialExecutor = true }
+  
   @Test
   func detailEdit() async throws {
     let syncUp = SyncUp.mock

Examples/SyncUps/SyncUpsTests/RecordMeetingTests.swift

@@ -6,6 +6,8 @@ import Testing
 
 @MainActor
 struct RecordMeetingTests {
+  init() { uncheckedUseMainSerialExecutor = true }
+  
   @Test
   func timer() async {
     let clock = TestClock()

Examples/SyncUps/SyncUpsTests/SyncUpDetailTests.swift

@@ -5,6 +5,8 @@ import Testing
 
 @MainActor
 struct SyncUpDetailTests {
+  init() { uncheckedUseMainSerialExecutor = true }
+  
   @Test
   func speechRestricted() async {
     let store = TestStore(initialState: SyncUpDetail.State(syncUp: Shared(.mock))) {

Examples/SyncUps/SyncUpsTests/SyncUpFormTests.swift

@@ -6,6 +6,8 @@ import Testing
 
 @MainActor
 struct SyncUpFormTests {
+  init() { uncheckedUseMainSerialExecutor = true }
+
   @Test
   func addAttendee() async {
     let store = TestStore(

Examples/SyncUps/SyncUpsTests/SyncUpsListTests.swift

@@ -6,6 +6,8 @@ import Testing
 
 @MainActor
 struct SyncUpsListTests {
+  init() { uncheckedUseMainSerialExecutor = true }
+  
   @Test
   func add() async throws {
     let store = TestStore(initialState: SyncUpsList.State()) {