Build.xml: on macOS, add /usr/local/lib to rpath when building lime.ndll

This seems to be required with Xcode 15, but was not required previously

project/Build.xml

@@ -442,6 +442,11 @@
 			</section>
 
 			<section if="mac">
+				<!--
+					starting in xcode 15, rpath doesn't automatically include
+					/usr/local/lib, but we need it for neko
+				-->
+				<vflag name="-rpath" value="/usr/local/lib" />
 
 				<vflag name="-l" value="iconv" />
 				<vflag name="-framework" value="IOKit" />