Fix "rm: no operand" error in clean-pyc script

[hankehly]

Description

make clean-pyc fails with the following error when there are no cache files to delete. We can fix this by adding the -r flag to xargs to prevent it from running on empty input.

$ docker compose -f docker/docker-compose.yml run --rm celery
[+] Running 4/0
 ⠿ Container docker-azurite-1   Running                                                                                                                                                                                                         0.0s
 ⠿ Container docker-redis-1     Running                                                                                                                                                                                                         0.0s
 ⠿ Container docker-dynamodb-1  Running                                                                                                                                                                                                         0.0s
 ⠿ Container docker-rabbit-1    Running                                                                                                                                                                                                         0.0s
rm: missing operand
Try 'rm --help' for more information.
rm: missing operand
Try 'rm --help' for more information.

Searching around, it looks like one other person has experienced this.

[auvipy]

thanks