[Release] Add changelog entry for #11151 (#11155)

* [Release] Add changelog entry for #11151

* Wrong CHANGELOG

* [Release] Add changelog entry for #11151

* Retroactively update Firestore 10.8.0 changelog

Author: ncooke3

Firestore/CHANGELOG.md

@@ -6,6 +6,7 @@
 - [feature] Change Firestore's Swift Package Manager distribution from source
   to binary to reduce the time it takes to add the Firebase package and to
   build the Firestore SDK (#6564).
+- [fixed] Fixed SSL symbol collision issue affecting SwiftPM users. (#6869)
 
 # 10.7.0
 - [feature] Add support for disjunctions in queries (`OR` queries).

Firestore/Swift/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 10.9.0
+- [changed] The async `CollectionReference.addDocument(data:)` API now returns
+  a discardable result. (#10640)
+
 # 10.4.0
 - [fixed] Restore 9.x Codable behavior of encoding `Data` types as an `NSData`
   blob instead of a String.