SDL_mixer: Added a note to create a new milestone after release

From 32fd3fe171738a2704126ad84e42824c33749fc8 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Thu, 7 Jul 2022 11:40:52 -0700
Subject: [PATCH] Added a note to create a new milestone after release

---
 release_checklist.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/release_checklist.md b/release_checklist.md
index c0722fdd..cfbc2b69 100644
--- a/release_checklist.md
+++ b/release_checklist.md
@@ -74,6 +74,8 @@
 
 * Run test/versioning.sh to verify that everything is consistent
 
+* Add a new milestone for issues
+
 ## New development prerelease
 
 * Bump version number from 2.Y.Z to 2.Y.(Z+1) (Y is odd)