[REGRESSION] `TextEdit::min_size` no longer honors `min_size.y`

**Describe the bug**
After upgrading from egui `0.33` to `0.34`, `TextEdit::singleline(...).min_size(vec2(_, height))` no longer respects the requested minimum height.

The same code worked in `0.33`. In `0.34`, width still behaves as expected, but the height falls back to the widget's internal single-line height.

**Expected behavior**
The `TextEdit` should honor `min_size.y`, the same way it did in egui `0.33`, so the widget can match the row height.

**Desktop (please complete the following information):**
- OS: Linux Ubuntu 24.04 LTS on Wayland
- Version 0.34.1

**Workarounds**

- `ui.add_sized(...)` can force the outer slot size, but it does not fully replace the old behavior because the inner text layout still uses the widget's natural height.
- Adjusting `TextEdit::margin(...)` can partially work around this, but it feels like a workaround for missing `min_size.y` handling rather than the intended API.

Start by reproducing the issue with TextEdit::singleline(...).min_size(vec2(_, height)) on egui 0.34.1, then compare its min_size handling with egui 0.33. The work is done when the requested min_size.y controls the single-line widget and the existing width behavior remains intact.

Written by the indexing model from the issue text.