openfoam: add mpfr search paths (#42779)

Co-authored-by: Branden Moore <branden.moore@amd.com>

var/spack/repos/builtin/packages/openfoam/package.py

@@ -689,11 +689,13 @@ def configure(self, spec, prefix):
             "CGAL": [
                 ("BOOST_ARCH_PATH", spec["boost"].prefix),
                 ("CGAL_ARCH_PATH", spec["cgal"].prefix),
+                ("MPFR_ARCH_PATH", spec["mpfr"].prefix),
                 (
                     "LD_LIBRARY_PATH",
                     foam_add_lib(
                         pkglib(spec["boost"], "${BOOST_ARCH_PATH}"),
                         pkglib(spec["cgal"], "${CGAL_ARCH_PATH}"),
+                        pkglib(spec["mpfr"], "${MPFR_ARCH_PATH}"),
                     ),
                 ),
             ],