fix(grid): don't crash if row doesn't exist

Signed-off-by: Akhil Narang <me@akhilnarang.dev>
(cherry picked from commit 31c6df2)

frappe/public/js/frappe/form/grid.js

@@ -213,7 +213,7 @@ export default class Grid {
 					this.df.data = this.get_data();
 					this.df.data = this.df.data.filter((row) => row.idx != doc.idx);
 				}
-				this.grid_rows_by_docname[doc.name].remove();
+				this.grid_rows_by_docname[doc.name]?.remove();
 				dirty = true;
 			});
 			tasks.push(() => frappe.timeout(0.1));