Bump to v0.1.18 (#295)

Author: Ubospica

python/xgrammar/version.py

@@ -20,7 +20,7 @@
 
 # ---------------------------------------------------
 
-__version__ = "0.1.17"
+__version__ = "0.1.18"
 PROJ_ROOT = os.path.dirname(os.path.abspath(os.path.expanduser(__file__)))