feat!: bump JS SDK to version 12.0.0 (#17548)

Update here: https://firebase.google.com/support/release-notes/js No actual breaking change, but noted some change in IndexDB that could cause breaking change behavior. Will keep this PR as breaking change to avoid mistakes

Author: Lyokone

packages/firebase_core/firebase_core_web/lib/src/firebase_sdk_version.dart

@@ -6,4 +6,4 @@
 part of '../firebase_core_web.dart';
 
 /// The currently supported Firebase JS SDK version.
-const String supportedFirebaseJsSdkVersion = '11.9.1';
+const String supportedFirebaseJsSdkVersion = '12.0.0';