app,create-app: migrate to wrapping <Navigate /> in a <Route />

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/itchy-owls-rescue.md

@@ -0,0 +1,13 @@
+---
+'@backstage/create-app': patch
+---
+
+Update the setup of the app routes in the template to wrap the `<Navigate .../>` redirect in a `<Route .../>`, as this will be required in `react-router` v6 stable.
+
+To apply this change to an existing app, make the following change to `packages/app/src/App.tsx`:
+
+```diff
+   <FlatRoutes>
+-    <Navigate key="/" to="catalog" />
++    <Route path="/" element={<Navigate to="catalog" />} />
+```

packages/app/src/App.tsx

@@ -145,7 +145,7 @@ const AppRouter = app.getRouter();
 
 const routes = (
   <FlatRoutes>
-    <Navigate key="/" to="catalog" />
+    <Route path="/" element={<Navigate to="catalog" />} />
     {/* TODO(rubenl): Move this to / once its more mature and components exist */}
     <Route path="/home" element={<HomepageCompositionRoot />}>
       {homePage}

packages/create-app/templates/default-app/packages/app/src/App.tsx

@@ -58,7 +58,7 @@ const AppRouter = app.getRouter();
 
 const routes = (
   <FlatRoutes>
-    <Navigate key="/" to="catalog" />
+    <Route path="/" element={<Navigate to="catalog" />} />
     <Route path="/catalog" element={<CatalogIndexPage />} />
     <Route
       path="/catalog/:namespace/:kind/:name"