fix(flutter/analytics): temporarily remove broken url (#6177)

Author: haverchuck

src/fragments/lib/project-setup/flutter/upgrade-guide/upgrade-guide.mdx

@@ -291,7 +291,7 @@ Follow the instructions [here](/lib/auth/social/q/platform/flutter/#platform-set
 - Automatic session reporting behavior has been aligned in v1. For all platforms, backgrounding and foregrounding the app will stop and start a new session. Previously on iOS, the session would pause and then resume.
 - You can now save to the `UserAttributes` field of a Pinpoint Endpoint by passing an `AWSPinpointUserProfile` to `identifyUser`.
 - Analytics cached event data is now stored differently. Existing cached analytics events will not be migrated.
-- There are now typed `AnalyticsException`s for specific exception cases. See [the documentation on Pub](https://pub.dev/documentation/amplify_analytics_pinpoint/latest/amplify_analytics_pinpoint/amplify_analytics_pinpoint-library.html) for a full list of exceptions.
+- There are now typed `AnalyticsException`s for specific exception cases.
 
 ## API