Proposed macOS patch for math/R

[Jason Bacon <jtocino%gmx.com@localhost>]

The following patch unbreaks build on macOS 13.5.  Let me know if there
is any reason not to commit it (please test on other macOS versions if
possible).  Thanks...

Index: Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/math/R/Makefile,v
retrieving revision 1.241
diff -u -r1.241 Makefile
--- Makefile    21 Jul 2023 22:46:50 -0000      1.241
+++ Makefile    26 Sep 2023 12:41:58 -0000
@@ -104,6 +104,10 @@

 CONFIGURE_ARGS.Darwin+=        --disable-openmp

+# Temporary fix for deprecated function ATSFontFindFromName()
+# https://trac.macports.org/ticket/66095
+MAKE_ENV.Darwin+= MACOSX_DEPLOYMENT_TARGET="12.0"
+
 # R_PAPERSIZE can be: A4, Letter, Legal, Executive
 .if defined(PAPERSIZE)
 R_PAPERSIZE?=          ${PAPERSIZE}