chore: Bump version to 1.9.1

Workflow run: https://github.com/HumanSignal/label-studio/actions/runs/6410731721

Author: jombooth

label_studio/__init__.py

@@ -4,7 +4,7 @@
 package_name = 'label-studio'
 
 # Package version
-__version__ = '1.9.1dev'
+__version__ = '1.9.1'
 
 # pypi info
 __latest_version__ = None