[cleanup] Remove unnecessary unconstrainedWidth var/check

- it literally isn't doing anything as a check 🤷

Author: cee-chen

packages/eui/src/components/datagrid/body/data_grid_body_virtualized.tsx

@@ -277,7 +277,6 @@ export const EuiDataGridBodyVirtualized: FunctionComponent<EuiDataGridBodyProps>
        */
       const { finalWidth, finalHeight } = useFinalGridDimensions({
         unconstrainedHeight,
-        unconstrainedWidth: 0, // unable to determine this until the container's size is known
         wrapperDimensions,
         wrapperRef,
         isFullScreen,

packages/eui/src/components/datagrid/utils/grid_height_width.ts

@@ -22,14 +22,12 @@ import { DataGridSortedContext } from './sorting';
 
 export const useFinalGridDimensions = ({
   unconstrainedHeight,
-  unconstrainedWidth,
   wrapperDimensions,
   wrapperRef,
   isFullScreen,
   rowCount,
 }: {
   unconstrainedHeight: number;
-  unconstrainedWidth: number;
   wrapperDimensions: { width: number; height: number };
   wrapperRef: MutableRefObject<HTMLDivElement | null>;
   isFullScreen: boolean;
@@ -69,16 +67,13 @@ export const useFinalGridDimensions = ({
   useEffect(() => {
     if (!wrapperRef.current) return;
     const wrapperWidth = wrapperRef.current.getBoundingClientRect().width;
-
-    if (wrapperWidth !== unconstrainedWidth) {
-      setWidth(wrapperWidth);
-    }
-  }, [wrapperDimensions.width, unconstrainedWidth, wrapperRef]);
+    setWidth(wrapperWidth);
+  }, [wrapperDimensions.width, wrapperRef]);
 
   const finalHeight = isFullScreen
     ? fullScreenHeight
     : height || unconstrainedHeight;
-  const finalWidth = width || unconstrainedWidth;
+  const finalWidth = width || 0;
 
   return IS_JEST_ENVIRONMENT
     ? {