Add explicit write transactions and deterministic ordering tests

GameList.Tests/AdminTests.cs

@@ -244,11 +244,11 @@ public class AdminTests
         {
             var p = await db.Players.FirstAsync(x => !x.IsAdmin);
             p.VotesFinal = true;
+            var state = await db.AppState.FirstAsync();
+            state.UpdatedAt = DateTimeOffset.UnixEpoch;
             await db.SaveChangesAsync();
         });
 
-        var beforeState = await factory.WithDbContextAsync(async db => await db.AppState.AsNoTracking().FirstAsync());
-        await Task.Delay(5);
         var close = await admin.PostAsJsonAsync("/api/admin/results", new { resultsOpen = false });
         close.EnsureSuccessStatusCode();
 
@@ -259,7 +259,7 @@ public class AdminTests
             Assert.False(p.VotesFinal);
             var state = await db.AppState.AsNoTracking().FirstAsync();
             Assert.False(state.ResultsOpen);
-            Assert.True(state.UpdatedAt > beforeState.UpdatedAt);
+            Assert.True(state.UpdatedAt > DateTimeOffset.UnixEpoch);
         });
     }