meson: Require Node.js >= 18 when GumJS is enabled

Our JavaScript runtime autogen doesn't need it just yet, but will once
we upgrade frida-compile. Another reason is that somebody is likely to
build frida-core after frida-gum. They might install some version < 18
when encountering the check in this project, only to be disappointed
when frida-core tells them they need a newer version.

meson.build

@@ -644,9 +644,13 @@ if have_gumjs
     'sysprof=disabled',
   ])
 
+  node = find_program('node', version: '>=18.0.0', native: true, required: false)
+  if not node.found()
+    error('Need Node.js >= 18.0.0 to process JavaScript code at build-time')
+  endif
   npm = find_program('npm', native: true, required: false)
   if not npm.found()
-    error('Need Node.js and npm to process JavaScript code at build-time')
+    error('Need npm to process JavaScript code at build-time')
   endif
 else
   v8_dep = disabler()