Belatedly bump version in docs

Author: akx

docs/conf.py

@@ -44,16 +44,16 @@
 
 # General information about the project.
 project = 'Babel'
-copyright = '2025, The Babel Team'
+copyright = '2026, The Babel Team'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 #
 # The short X.Y version.
-version = '2.17'
+version = '2.18'
 # The full version, including alpha/beta/rc tags.
-release = '2.17.0'
+release = '2.18.0'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.