Remove polyfil.io reference from warning message (#11741)

Author: brophdawg11

.changeset/flat-seals-hunt.md

@@ -0,0 +1,5 @@
+---
+"react-router-dom": patch
+---
+
+Remove `polyfill.io` reference from warning message because the domain was sold and has since been determined to serve malware. See https://sansec.io/research/polyfill-supply-chain-attack.

packages/react-router-dom/index.tsx

@@ -1464,11 +1464,7 @@ export function useSearchParams(
     `You cannot use the \`useSearchParams\` hook in a browser that does not ` +
       `support the URLSearchParams API. If you need to support Internet ` +
       `Explorer 11, we recommend you load a polyfill such as ` +
-      `https://github.com/ungap/url-search-params\n\n` +
-      `If you're unsure how to load polyfills, we recommend you check out ` +
-      `https://polyfill.io/v3/ which provides some recommendations about how ` +
-      `to load polyfills only for users that need them, instead of for every ` +
-      `user.`
+      `https://github.com/ungap/url-search-params.`
   );
 
   let defaultSearchParamsRef = React.useRef(createSearchParams(defaultInit));