security/p11-kit: Use base system CA certificates

Drop dependency on ca_root_nss and use base system root certificates
instead. This allows users to add their own certificates.

trust_paths now points to a directory and that directory contains
"anchors" and "blocklist" symlinks pointing to the base system
certificate directories. This is based on the documentation from
https://p11-glue.github.io/p11-glue/p11-kit/manual/trust-module.html.
The list of certificates known to p11-kit can be verified by running
"trust list".

PR: 268841
Approved by: novel (maintainer)