SDL_ttf: update vendored harfbuzz (da84b)

From da84bcebd3a767c4be94682321802fc81308a996 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Sat, 6 Jan 2024 14:01:04 +0300
Subject: [PATCH] update vendored harfbuzz

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

diff --git a/external/harfbuzz b/external/harfbuzz
index c248ad5..516b7ed 160000
--- a/external/harfbuzz
+++ b/external/harfbuzz
@@ -1 +1 @@
-Subproject commit c248ad57f98c3b069b80e6b5223c6f5ab082f15d
+Subproject commit 516b7ed0b022ab0ffeb0cee87d31d9c40d3a54df