Drop warnings enable filter
Drop warnings enable filter

[1] Enabled warnings without specifying category,
leading to all sort of warnings enabled, this patch
drops it and let it to consumers to enable warnings
types which they are interested in.

[1] https://review.opendev.org/c/openstack/oslo.utils/+/790429

Closes-Bug: #1934098
Change-Id: I822138c18e0932e8f7e3dc62267f167876c962ae

openstack/oslo.utils