GRDB: Don't mention outdated session hack

Author: simolus3

client-sdks/orms/swift/grdb.mdx

@@ -15,7 +15,6 @@ There are some limitations to be aware of:
 
 - Updating the PowerSync schema using `updateSchema` is not yet supported. 
 - Xcode previews may not yet work correctly. 
-- The current implementation uses the SQLite session API for change tracking, which may consume more memory than the standard PowerSync implementation. A more efficient tracking mechanism is planned.
 - You may see thread priority inversion warnings in Xcode. We're working to ensure consistent quality-of-service classes across threads.
 - The schema definition process requires manually defining both the PowerSync `AppSchema` and GRDB record types separately. Future versions may allow these to be declared together or derived from each other.
 </Note>