Remove util/update_lints.py

This has been deprecated for ~10 months, so I think it's fine to remove now.

util/update_lints.py

@@ -1,10 +0,0 @@
-#!/usr/bin/env python
-
-import sys
-
-def main():
-    print('Error: Please use `util/dev` to update lints')
-    return 1
-
-if __name__ == '__main__':
-    sys.exit(main())