Fix with pinned filters IndexFilters example on website (#12759)

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### WHY are these changes introduced?

Fixes #0000 <!-- link to issue if one exists -->

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### How to 🎩

🖥 [Local development
instructions](https://github.com/Shopify/polaris/blob/main/README.md#install-dependencies-and-build-workspaces)
🗒 [General tophatting
guidelines](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md)
📄 [Changelog
guidelines](https://github.com/Shopify/polaris/blob/main/.github/CONTRIBUTING.md#changelog)

### 🎩 checklist

- [ ] Tested a
[snapshot](https://github.com/Shopify/polaris/blob/main/documentation/Releasing.md#-snapshot-releases)
- [ ] Tested on
[mobile](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md#cross-browser-testing)
- [ ] Tested on [multiple
browsers](https://help.shopify.com/en/manual/shopify-admin/supported-browsers)
- [ ] Tested for
[accessibility](https://github.com/Shopify/polaris/blob/main/documentation/Accessibility%20testing.md)
- [ ] Updated the component's `README.md` with documentation changes
- [ ] [Tophatted
documentation](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting%20documentation.md)
changes in the style guide

polaris.shopify.com/pages/examples/index-filters-with-pinned-filters.tsx

@@ -191,7 +191,7 @@ function IndexFiltersWithPinnedFiltersExample() {
           allowMultiple
         />
       ),
-      shortcut: true,
+      pinned: true,
     },
     {
       key: 'taggedWith',
@@ -205,7 +205,7 @@ function IndexFiltersWithPinnedFiltersExample() {
           labelHidden
         />
       ),
-      shortcut: true,
+      pinned: true,
     },
     {
       key: 'moneySpent',