Wrong test assertion in Test_Span2D{T}

### Describe the bug

In this test we check that array is equals to itself but probably it should be compared with span2d or with a constant expected value.

https://github.com/CommunityToolkit/dotnet/blob/b8df95a9f3531524209b4bf483f684a1c52e30a9/tests/CommunityToolkit.HighPerformance.UnitTests/Memory/Test_Span2D%7BT%7D.cs#L296-L316

### Regression

_No response_

### Steps to reproduce

```text
1. Open the code :)
```

### Expected behavior

the array should be compared with the span2d variable or with a constant expected value.

### Screenshots

_No response_

### IDE and version

VS 2022

### IDE version

_No response_

### Nuget packages

- [ ] CommunityToolkit.Common
- [ ] CommunityToolkit.Diagnostics
- [ ] CommunityToolkit.HighPerformance
- [ ] CommunityToolkit.Mvvm (aka MVVM Toolkit)

### Nuget package version(s)

Doesn't matter

### Additional context

_No response_

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