Remove SkMatrix44

Change-Id: I4b33603f7318bc5881929b50258bf166c8a5cb04
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/420818
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
diff --git a/RELEASE_NOTES.txt b/RELEASE_NOTES.txt
index fe0768c..87b0d7e 100644
--- a/RELEASE_NOTES.txt
+++ b/RELEASE_NOTES.txt
@@ -2,6 +2,8 @@
 
 This file includes a list of high level updates for each milestone release.
 
+  * Removed SkMatrix44
+
 * * *
 
 Milestone 93