[Bug]: [TUnit.Assertions.Should] `Should().HaveSingleItem()` returns `int[]` instead of `int`

[kzrnm]

Description

// OK
await (await Assert.That(new int[1] { 1 }).HasSingleItem()).Should().BeOfType(typeof(int));

// NG
await (await new int[1] { 1 }.Should().HaveSingleItem()).Should().BeOfType(typeof(int));

Expected Behavior

new int[1] { 1 }.Should().HaveSingleItem() returns int.

Actual Behavior

new int[1] { 1 }.Should().HaveSingleItem() returns IEnumerable.

Steps to Reproduce

// OK
await (await Assert.That(new int[1] { 1 }).HasSingleItem()).Should().BeOfType(typeof(int));

// NG
await (await new int[1] { 1 }.Should().HaveSingleItem()).Should().BeOfType(typeof(int));

TUnit Version

1.56.35

.NET Version

.NET 9

Operating System

Windows

IDE / Test Runner

dotnet CLI (dotnet test / dotnet run)

Error Output / Stack Trace

Additional Context

No response

IDE-Specific Issue?

• I've confirmed this issue occurs when running via dotnet test or dotnet run, not just in my IDE