fix(components): fix the problem that chrome 72 table doesnotdisplayd…

…ata (element-plus#10640)

Fix the problem that the chrome 72 tab table does not display data. This is caused by the fact that
the extension operator becomes an empty object in a special scenario

BREAKING CHANGE :
The writing method of shallow copy is replaced

closed element-plus#8770,element-plus#9071,element-plus#7038

Co-authored-by: btea <2356281422@qq.com>

packages/components/table/src/table-body/render-helper.ts

@@ -79,7 +79,7 @@ function useRender<T>(props: Partial<TableBodyProps<T>>) {
         if (!rowspan || !colspan) {
           return null
         }
-        const columnData = { ...column }
+        const columnData = Object.assign({}, column)
         columnData.realWidth = getColspanRealWidth(
           columns.value,
           colspan,