[125% DPI] TextBox and MaskedTextBox render incorrect bottom border and accent focus stroke #15128

.NET version

.NET 11 RC2 build + integration/11.0-RC2 branch of Winforms repo

Did it work in .NET Framework?

Not tested/verified

Did it work in any of the earlier releases of .NET Core or .NET 5+?

NET11 new APIs

Issue description

When running at 125% DPI with VisualStylesMode.Net11, the bottom border of TextBox and MaskedTextBox is not rendered correctly.
The issue is especially noticeable around the bottom-left and bottom-right rounded corners, where the bottom border does not connect smoothly with the side borders.

The issue also occurs in the focused state. The accent-colored bottom focus indicator shows incorrect rendering around both rounded corners.

This issue only reproduces at 125% DPI scaling.

Steps to reproduce

1. Create a WinForms application targeting .NET 11.
2. Set VisualStylesMode = VisualStylesMode.Net11.
3. Add a TextBox and a MaskedTextBox to the Form.
4. Set the Windows display scaling to 125%.
5. Build and run the application.
6. Observe the bottom border of the TextBox and MaskedTextBox.
7. Give each control focus and observe the accent-colored bottom focus indicator.