Steps to reproduce:
1. Create a new project
2. Right-click in the Project window > Create > UI Toolkit > UI Document
3. Open the newly created UI Document (UI Builder window should open)
4. Drag and drop a “VisualElement” from the Library tab to the Hierarchy tab (add as many as you like)
5. In the Viewport, select any of the newly added elements
6. Try resizing it by dragging any of its borders or the bottom-right corner

Expected result: The element is being resized without any glitching
Actual result: The element’s borders flicker and jump around

Reproducible with: 2021.3.35f1, 2022.3.19f1, 2023.2.9f1, 2023.3.0b6

Reproduced on: Windows 11 Pro (23H2)
Not reproduced on: No other environment tested

Notes:
- Only the elements that belong to the “Numeric Fields” category in the Library tab, do not seem to be affected by the issue
- Having only 1 element in the Viewport reproduces the issue the most consistently when resizing the element beyond the size of the UI Document, otherwise the issue reproduces whenever other elements are affected by the element that is being resized