[tools] backport_node.py increments V8 version in target.

tools/release/test_backport_node.py

Index: tools/release/test_backport_node.py
diff --git a/tools/release/test_backport_node.py b/tools/release/test_backport_node.py
index 99aeccfe5df1a80aeda3a8a102e16bd18ed14961..a2be9cf33d8c820a46edd3506b4a2a0b76c4288d 100755
--- a/tools/release/test_backport_node.py
+++ b/tools/release/test_backport_node.py
@@ -10,6 +10,7 @@ import sys
 import tempfile
 import unittest
 
+from common_includes import FileToText
 import backport_node
 
 # Base paths.
@@ -62,5 +63,9 @@ class TestUpdateNode(unittest.TestCase):
     )
     self.assertIn('+zonk', gitlog.strip())
 
+    # Check version.
+    version_file = os.path.join(node_cwd, "deps", "v8", "include", "v8-version.h")
+    self.assertIn('#define V8_PATCH_LEVEL 4322', FileToText(version_file))
+
 if __name__ == "__main__":
   unittest.main()