Remove init_pod script

Summary

The init_pod.sh script did 3 things:

• Put the logs in /mnt/logs. This was not necessary; it was not crucial for the tests and the monitoring chart has been updated to not require this.
• Set the kernel core pattern. This is now done in the minikube cta ci setup
• Fix reverse DNS for XRootD. This was only necessary in the old kubernetes versions

Additional Required Actions

• Requires manual tests in pre-production: NO
• Requires a documentation update: NO

References

Closes #1107 (closed)