docs(script): fix python3 data type error

Author: dongheng

docs/gen-version-specific-includes.py

@@ -162,6 +162,8 @@ def get_version():
     # Otherwise, use git to look for a tag
     try:
         tag = subprocess.check_output(["git", "describe", "--tags", "--exact-match"]).strip()
+        if isinstance(tag, bytes):
+            tag = tag.decode()
         is_stable = re.match(r"v[0-9\.]+$", tag) is not None
         return (tag, "tag", is_stable)
     except subprocess.CalledProcessError: