[bug]: unexpected margin between multiple pinned columns in useDataTable columnPinning #913

Issue Description

When using the columnPinning feature in useDataTable to freeze multiple columns, I've noticed that an unexpected margin/gap appears between the pinned columns. This creates a discontinuous UI appearance, affecting the overall visual experience and usability of the table.

Create a data table using useDataTable

Configure columnPinning to pin multiple columns (e.g., columnPinning: { left: ['column1', 'column2', 'column3'] })
Render the table and observe the result
Notice the unexpected gaps/margins between the pinned columns

Expected Behavior

When multiple columns are pinned, they should appear tightly connected without any extra margins or gaps between them, visually presenting as one continuous pinned area.
Actual Behavior
There are noticeable gaps/margins between multiple pinned columns, making the pinned area look disconnected and breaking the visual integrity of the table.
Environment Information

How to reproduce

Link to reproduction

https://github.com/sadmann7/shadcn-table/blob/main/src/app/_components/tasks-table.tsx