src: update NODE_MODULE_VERSION to 138

Major V8 updates are usually API/ABI incompatible with previous
versions. This commit adapts NODE_MODULE_VERSION for V8 13.7.

Refs: https://github.com/nodejs/CTC/blob/master/meetings/2016-09-28.md

Author: targos

doc/abi_version_registry.json

@@ -1,5 +1,6 @@
 {
   "NODE_MODULE_VERSION": [
+    { "modules": 138,"runtime": "node",     "variant": "v8_13.7",              "versions": "24.0.0-pre" },
     { "modules": 137,"runtime": "node",     "variant": "v8_13.6",              "versions": "24.0.0-pre" },
     { "modules": 136,"runtime": "electron", "variant": "electron",             "versions": "37" },
     { "modules": 135,"runtime": "electron", "variant": "electron",             "versions": "36" },

src/node_version.h

@@ -95,7 +95,7 @@
 #if defined(NODE_EMBEDDER_MODULE_VERSION)
 #define NODE_MODULE_VERSION NODE_EMBEDDER_MODULE_VERSION
 #else
-#define NODE_MODULE_VERSION 137
+#define NODE_MODULE_VERSION 138
 #endif
 
 // The NAPI_VERSION supported by the runtime. This is the inclusive range of