Fix horizontal scrolling with dir="rtl" for vaadin-tabs #2248
Description
Description
There is a test for the vaadin-tabs 3.2 that fails on certain unclear conditions. Test fails on Chrome 91 running on Windows 10. The test passes on macOS Big Sur but it's a false positive since the actual behavior is somewhat unintended.
Worth mentioning that the test also fails with Gihub Actions which doesn't run on any of the aforementioned systems.
Expected outcome
On Windows 10:
The left-hand side chevron should disappear when scrolling to the end (left-hand side, since it's dir="rtl") and the overflow attribute should not have end in its value.
On macOS:
The left-hand side chevron should appear and the overflow attribute should have end in its value when the tabs' scroll position is not at the end (left-hand side, since it's dir="rtl").
Actual outcome
On Windows 10:
When scrolling the tabs to the far left hand side, the overflow attribute keeps its value of start end and the scroll chevron never disappears.
On macOS Big Sur:
The left-hand side chevron never appears, and the overflow attribute never has end in its value, regardless of the scroll position.
Live Demo (optional)
Windows 10, Chrome 91, at the end of scrollable area
macOS Big Sur, Chrome 91, not at the end of scrollable area
Minimal reproducible example
Run the demos for vaadin-tabs 3.2 and go to "Scrollable horizontal tabs". Edit it in devtools to add dir="rtl" to the demo body or the component itself.