FontSize is not consistent between TextBlock and TextBox since WinAppSDK 1.6

### Describe the bug

Since the update to WinAppSDK 1.6, there is an inconsistency between TextBlock and TextBox controls regarding FontSize (and LineHeight when the FontSize is increased to match). This discrepancy results in misalignment and rendering issues, impacting the visual consistency of text across different controls.

### Steps to reproduce the bug

Create a new application with WinAppSDK 1.6 and add the following XAML. Observe that the FontSize does not match.

```XAML

```

### Expected behavior

FontSize of TextBlock and TextBlock should be consistent

### Screenshots

Red: TextBox
Blue: TextBlock

**WinAppSDK 1.5:**

**WinAppSDK 1.6:**

### NuGet package version

Windows App SDK 1.6.0: 1.6.240829007

### Packaging type

Packaged (MSIX), Unpackaged

### Windows version

Insider Build (xxxxx)

### IDE

Visual Studio 2022

### Additional context

_No response_

Reproduce the supplied XAML with Windows App SDK 1.5 and 1.6, comparing the TextBox and TextBlock rendering at FontSize 13 and the adjusted LineHeight. Trace the desktop control styling or rendering entry points responsible for these controls; done means matching font size and alignment without the reported discrepancy.

Written by the indexing model from the issue text.