Timeseries: Two points with same x-axis may not render points

reported by @gtk-grafana A weird case I ran into while testing was that when you have 2 or more points with the same x and y-axis values is that the datapoints only show on hover, making the graph appear empty until you happen to hover. This behavior also occurs on main, although the main behavior the datapoint is not centered but moved to the top left of the panel, and the data point is not rendered in the correct place on the y-axis, but the datapoint is shown when hovering near the y-axis value for the point: Main: <img width="1721" height="1040" alt="Image" src="https://github.com/user-attachments/assets/f9d78329-d447-414d-a206-23bd522d5d07" /> Multiple points with same x-axis value (buggy): <img width="1691" height="827" alt="Image" src="https://github.com/user-attachments/assets/15d91e20-f16c-43b7-aa3c-10d3b948bd60" /> Only shows on hover: <img width="1693" height="827" alt="Image" src="https://github.com/user-attachments/assets/94eb1fc0-8561-402b-b19e-fe85ab03db03" /> One point (expected behavior): <img width="1701" height="827" alt="Image" src="https://github.com/user-attachments/assets/e18031e5-e7ab-495a-8d9b-f933d29f02b9" />