SDL_image: libwebp: update vendored library (9bb60)

From 9bb60396fea12e552f62940f200a7a410efa4c9c Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Wed, 8 Feb 2023 23:37:32 +0300
Subject: [PATCH] libwebp: update vendored library

---
 external/libwebp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/external/libwebp b/external/libwebp
index 485750ef..acf204e2 160000
--- a/external/libwebp
+++ b/external/libwebp
@@ -1 +1 @@
-Subproject commit 485750ef77691883d770b6813e611b1e9c07012c
+Subproject commit acf204e2908c66d0fba88e6b5a3daeedbe4a5779