chore(release): Bumped to Version 15.31.0

# [15.31.0](v15.30.0...v15.31.0) (2024-10-07)

### Features

* allow get_first_day and get_last_day in salary slip eval ([f938cff](f938cff))
* show In and Out Time in Attendance even if there is only one log ([1c72b9a](1c72b9a))

hrms/__init__.py

@@ -1,6 +1,6 @@
 import frappe
 
-__version__ = "15.30.0"
+__version__ = "15.31.0"
 
 
 def refetch_resource(cache_key: str | list, user=None):