Add release notes for 3.7.3-RC3

Signed-off-by: Wojciech Mazur <[email protected]>

Author: WojciechMazur

changelogs/3.7.3-RC3.md

@@ -0,0 +1,14 @@
+# Backported chnages
+
+- Update scala-cli to 1.9.0 (was 1.8.5) [#23861](https://github.com/scala/scala3/pull/23861)
+
+
+# Contributors
+
+Thank you to all the contributors who made this release possible 🎉
+
+According to `git shortlog -sn --no-merges 3.7.3-RC2..3.7.3-RC3` these are:
+
+```
+  3 Wojciech Mazur
+```