[integration_test] Fix link to integration test for web section in README.md (#103422)

* [integration_test] Fix link to integration test for web section in `README.md`

* Update packages/integration_test/README.md

* Update packages/integration_test/README.md

Author: nilsreichardt

packages/integration_test/README.md

@@ -86,7 +86,7 @@ flutter drive \
 ### Web
 
 Make sure you have [enabled web support](https://flutter.dev/docs/get-started/web#set-up)
-then [download and run](https://flutter.dev/docs/cookbook/testing/integration/introduction#6b-web)
+then [download and run](https://docs.flutter.dev/cookbook/testing/integration/introduction#5b-web)
 the web driver in another process.
 
 Use following command to execute the tests: