fix: Update import from castle_api.tools to castle_api.programs

The tools.py file was renamed to programs.py but the import in
main.py was not updated in the previous commit.

castle-api/src/castle_api/main.py

@@ -26,7 +26,7 @@ from castle_api.stream import (
     unsubscribe,
 )
 from castle_api.nodes import router as nodes_router
-from castle_api.tools import programs_router
+from castle_api.programs import programs_router
 
 logger = logging.getLogger(__name__)