libobs: Update version to 31.1.2

libobs/obs-config.h

@@ -41,7 +41,7 @@
  *
  * Reset to zero each major or minor version
  */
-#define LIBOBS_API_PATCH_VER 1
+#define LIBOBS_API_PATCH_VER 2
 
 #define MAKE_SEMANTIC_VERSION(major, minor, patch) ((major << 24) | (minor << 16) | patch)