Update libvips to v8.15.4 (#5445)

packages/l/libvips/xmake.lua

@@ -6,6 +6,7 @@ package("libvips")
     add_urls("https://github.com/libvips/libvips/archive/refs/tags/$(version).tar.gz",
              "https://github.com/libvips/libvips.git")
 
+    add_versions("v8.15.4", "16afc1bf2218a98c1dc35ec4d94ef61d66c293eeb2b399fd40282dfb2211ea95")
     add_versions("v8.15.3", "c23a820443241c35e62f1f1f0a1f6c199b37e07d98e3268a7fa9db43309fd67d")
     add_versions("v8.15.2", "8c3ece7be367636fd676573a8ff22170c07e95e81fd94f2d1eb9966800522e1f")
     add_versions("v8.15.1", "5701445a076465a3402a135d13c0660d909beb8efc4f00fbbe82392e243497f2")