chore: Remove v9 changelog because it is now part of the default changelog (#6637)

Author: noahsmartin

CHANGELOG-v9.md

@@ -12,6 +12,9 @@
 - Removes deprecated getStoreEndpoint (#5591)
 - Remove legacy profiling, the only supported profiling is now what was known as continuous V2 (#6386)
 - Removes deprecated useSpan function (#5591)
+- Makes app hang tracking V2 the default and removes the option to enable/disable it (#5615)
+- Removes `integrations` property from `SentryOptions` (#5749)
+- Makes `SentryEventDecodable` internal (#5808)
 - The `span` property on `SentryScope` is now readonly (#5866)
 - Removes deprecated SentryDebugImageProvider class (#5598)
 - Removes segment property on SentryUser, SentryBaggage, and SentryTraceContext (#5638)