Update pymunk_demo_platformer_11.py

[ultibo]

fixed an error when testing step11 "AttributeError: module 'arcade.tilemap' has no attribute 'process_layer'"

when you run the step 11 the following line 230 caused an error when trying to run the file. self.moving_sprites_list = arcade.tilemap.process_layer(my_map, 'Moving Platforms', SPRITE_SCALING_TILES)

AttributeError: module 'arcade.tilemap' has no attribute 'process_layer'

[einarf]

Note that this is a fix for the maintenance branch

[ultibo]

Hello, I saw previous message indicating some tests have failed. I'm not sure of what to do next.