SDL_image: cmake: need to enable testing in the test subfolder

SDL Commits
1 
From bff1d52713a039a4908cfe6b11f4b5399b997696 Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <[EMAIL REDACTED]>
Date: Sat, 9 Sep 2023 02:58:50 +0200
Subject: [PATCH] cmake: need to enable testing in the test subfolder

---
 test/CMakeLists.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 45c8c532..90a4b8cf 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,3 +1,5 @@
+enable_testing()
+
 if(NOT TARGET SDL2::SDL2main)
     find_package(SDL2main)
 endif()