Average_Grouped_from_LINQ_101 is non-deterministic

[roji]

In:

public virtual Task Average_Grouped_from_LINQ_101(bool async)
    => AssertQuery(
        async,
        ss => from p in ss.Set<ProductForLinq>()
              group p by p.Category
              into g
              select new { Category = g.Key, AveragePrice = g.Average(p => p.UnitPrice) },
        ss => from p in ss.Set<ProductForLinq>()
              group p by p.Category
              into g
              select new { Category = g.Key, AveragePrice = Math.Round(g.Average(p => p.UnitPrice) - 0.0000005m, 6) });

There is no entity sorter configure, so the order is non-deterministic (fails on PG).

Same with Whats_new_2021_sample_10.

[roji]

@maumar this is still failing on PG, but this time because of rounding accuracy:

Expected: { Category = Condiments, AveragePrice = 22.308333 }
Actual:   { Category = Condiments, AveragePrice = 22.3083333333333333 }

... because the test implementation rounds on the expected side, presumably to match SQL Server behavior:

public virtual Task Average_Grouped_from_LINQ_101(bool async)
    => AssertQuery(
        async,
        ss => from p in ss.Set<ProductForLinq>()
              group p by p.Category
              into g
              select new { Category = g.Key, AveragePrice = g.Average(p => p.UnitPrice) },
        ss => from p in ss.Set<ProductForLinq>()
              group p by p.Category
              into g
              select new { Category = g.Key, AveragePrice = Math.Round(g.Average(p => p.UnitPrice) - 0.0000005m, 6) },
        elementSorter: e => (e.Category, e.AveragePrice));

I see that InMemory also overrides, probably because of this rounding - should we move the rounding to SQL Server rather than imposing it on all providers by default?