Fix duplicate grid control keys (#6474)

**Problem:**

The grid controls show a bunch of duplicate keys while active.

**Fix:**

The problem is that there may be multiple instances of the same grid
being rendered caused by how they are initialized, so this PS cleans
that up.

Fixes #6473

editor/src/components/canvas/controls/grid-controls.tsx

@@ -20,7 +20,7 @@ import {
   printGridCSSNumber,
 } from '../../../components/inspector/common/css-utils'
 import { MetadataUtils } from '../../../core/model/element-metadata-utils'
-import { mapDropNulls, stripNulls } from '../../../core/shared/array-utils'
+import { mapDropNulls, stripNulls, uniqBy } from '../../../core/shared/array-utils'
 import { defaultEither } from '../../../core/shared/either'
 import * as EP from '../../../core/shared/element-path'
 import type {
@@ -1137,7 +1137,7 @@ export const GridControls = controlForStrategyMemoized<GridControlsProps>(({ tar
     'GridControls hoveredGrids',
   )
 
-  const grids = useGridData([...targets, ...hoveredGrids])
+  const grids = useGridData(uniqBy([...targets, ...hoveredGrids], (a, b) => EP.pathsEqual(a, b)))
 
   if (grids.length === 0) {
     return null