database.upgrade:upgrade_last - remove unneeded function

Can use a lambda with the same behaviour

acacore/database/upgrade.py

@@ -148,10 +148,6 @@ def upgrade_3to3_0_2(conn: Connection) -> Version:
     return set_db_version(conn, Version("3.0.2"))
 
 
-def upgrade_last(conn: Connection) -> Version:
-    return set_db_version(conn, Version(__version__))
-
-
 def get_upgrade_function(current_version: Version, latest_version: Version) -> Callable[[Connection], Version]:
     if current_version < Version("2.0.0"):
         return upgrade_1to2
@@ -162,7 +158,7 @@ def get_upgrade_function(current_version: Version, latest_version: Version) -> C
     elif current_version < Version("3.0.2"):
         return upgrade_3to3_0_2
     elif current_version < latest_version:
-        return upgrade_last
+        return lambda c: set_db_version(c, Version(__version__))
     else:
         return lambda _: latest_version