Update dependency single-spa to v6

Author: renovate[bot]

package.json

@@ -42,7 +42,7 @@
     "redux": "4.2.1",
     "redux-logger": "3.0.6",
     "redux-thunk": "3.1.0",
-    "single-spa": "5.9.4",
+    "single-spa": "6.0.3",
     "typeface-roboto": "1.1.13",
     "typescript": "5.9.2",
     "vite": "5.4.20"