docs: fix typo in grid generateCellPartNames typings (#11629) (#11633)

Co-authored-by: Serhii Kulykov <iamkulykov@gmail.com>

Author: vaadin-bot

packages/grid/src/vaadin-grid-styling-mixin.d.ts

@@ -34,7 +34,7 @@ export declare class StylingMixinClass<TItem> {
   cellPartNameGenerator: GridCellPartNameGenerator<TItem> | null | undefined;
 
   /**
-   * Runs the `cellPastNameGenerator` for the visible cells.
+   * Runs the `cellPartNameGenerator` for the visible cells.
    * If the generator depends on varying conditions, you need to
    * call this function manually in order to update the styles when
    * the conditions change.