add deprecation for watchOS (#10274)

* add deprecation for watchOS

* fix style script mangling link and run style

* rephrase deprecation message

* Add changelog

Author: morganchen12

FirebaseDatabase/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 10.0.0
+- [deprecated] Deprecated `FirebaseDatabase` on watchOS 9 and above.
+  watchOS users should instead use the Database REST API directly (#19272).
+
 # 9.6.0
 - [fixed] Fix priority inversion issue exposed by Xcode 14. (#10130)
 

FirebaseDatabase/Sources/Public/FirebaseDatabase/FIRDatabase.h

@@ -26,7 +26,12 @@ NS_ASSUME_NONNULL_BEGIN
  * by calling `Database.database()`. To access a location in the database and
  * read or write data, use `FIRDatabase.reference()`.
  */
-NS_SWIFT_NAME(Database)
+NS_SWIFT_NAME(Database) __attribute__((availability(
+    watchos, introduced = 6.0, deprecated = 9.0,
+    message = "Socket connections are not supported on watchOS 9.0 and higher. "
+              "Use the Firebase Database REST API instead. See "
+              "github.com/firebase/firebase-ios-sdk/issues/10195 "
+              "for more details.")))
 @interface FIRDatabase : NSObject
 
 /**