libofx: fix detection of OpenSP

If homebrew is not installed in /usr/local, libofx would not find
open-sp. Fix it by explicitly setting open-sp include and lib
directories.

Closes #31549.

Signed-off-by: Dominyk Tiller <dominyktiller@gmail.com>

Formula/libofx.rb

@@ -14,7 +14,10 @@ class Libofx < Formula
   depends_on "open-sp"
 
   def install
+    opensp = Formula["open-sp"]
     system "./configure", "--disable-dependency-tracking",
+                          "--with-opensp-includes=#{opensp.opt_include}/OpenSP",
+                          "--with-opensp-libs=#{opensp.opt_lib}",
                           "--prefix=#{prefix}"
     system "make", "install"
   end