json-c: update to 0.18

Also use release tarball and remove workaround for old postgis2.

textproc/json-c/Portfile

@@ -1,13 +1,11 @@
 # -*- coding: utf-8; mode: tcl; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- vim:fenc=utf-8:ft=tcl:et:sw=4:ts=4:sts=4
 
 PortSystem          1.0
-PortGroup           cmake 1.1
+PortGroup           cmake 1.0
 PortGroup           github 1.0
 PortGroup           muniversal 1.0
 
-github.setup        json-c json-c 0.17-20230812 json-c-
-# Change github.tarball_from to 'releases' or 'archive' next update
-github.tarball_from tarball
+github.setup        json-c json-c 0.18 json-c- -20240915
 revision            0
 license             MIT
 categories          textproc devel
@@ -20,18 +18,16 @@ long_description    JSON-C implements a reference counting object model that all
                     formatted strings and parse JSON formatted strings back into \
                     the C representation of JSON objects.
 
-checksums           rmd160  96d10e9335158a8669730d8d356a4b208cb4322c \
-                    sha256  0b26769642817955af2c0baa343757c736ce6e2c37238e9072b6851cee2702be \
-                    size    364532
+master_sites        https://s3.amazonaws.com/json-c_releases/releases/
+distfiles           ${name}-${version}-nodoc${extract.suffix}
+checksums           md5 e795aadd85376623777ff0fd259bebab \
+                    rmd160 c563f362ba81d831d9b1ab1abd6f0d9e70881b85 \
+                    sha256 602cdefc1d2aab8318fc0814b7ce7d59e72514d4276ca3eff92f35f86cf1c160
+
+cmake.out_of_source yes
 
 # disable warnings as errors, fixes:
 # cc1: warnings being treated as errors
 # json_object.c:73: warning: 'cold' attribute directive ignored
 # make[2]: *** [CMakeFiles/json-c.dir/build.make:125: CMakeFiles/json-c.dir/json_object.c.o] Error 1
 configure.args-append -DDISABLE_WERROR=ON
-
-# Add missing header file json_object_private.h.
-# See https://trac.macports.org/ticket/55647
-post-destroot {
-    copy ${worksrcpath}/json_object_private.h ${destroot}${prefix}/include/json-c/
-}