Remove EF query warnings from test runs

Endpoints/AdminWorkflowService.cs

@@ -9,7 +9,7 @@ internal sealed class AdminWorkflowService(AppDbContext db)
 {
     public async Task<IResult> SetResultsOpenAsync(bool resultsOpen)
     {
-        var state = await db.AppState.FirstAsync();
+        var state = await db.AppState.SingleAsync();
         state.ResultsOpen = resultsOpen;
         state.UpdatedAt = DateTimeOffset.UtcNow;
 
@@ -26,7 +26,7 @@ internal sealed class AdminWorkflowService(AppDbContext db)
 
         await db.SaveChangesAsync();
         await tx.CommitAsync();
-        var currentState = await db.AppState.AsNoTracking().FirstAsync();
+        var currentState = await db.AppState.AsNoTracking().SingleAsync();
         return Results.Ok(new AdminResultsStateResponse(currentState.ResultsOpen, currentState.UpdatedAt));
     }
 
@@ -186,7 +186,7 @@ internal sealed class AdminWorkflowService(AppDbContext db)
         await db.Suggestions.ExecuteDeleteAsync();
 
         await db.Players.ExecuteUpdateAsync(p => p.SetProperty(x => x.CurrentPhase, Phase.Suggest).SetProperty(x => x.VotesFinal, false).SetProperty(x => x.HasJoker, false));
-        var state = await db.AppState.FirstAsync();
+        var state = await db.AppState.SingleAsync();
         state.ResultsOpen = false;
         state.UpdatedAt = DateTimeOffset.UtcNow;
         await db.SaveChangesAsync();