Added tests for pid-file deletion in DaemonMixIn
Added tests for pid-file deletion in DaemonMixIn

This is a follow up on this PR:
https://github.com/saltstack/salt/pull/43366

Since we can get an OSError durin PIDfile deletion with non-root users, it
would make sense to also test for this. So here are the two test cases.
One with an OSError and the other one without.

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt