Security update for unbound

This update for unbound fixes the following issues:

unbound was updated to 1.20.0:

• A lot of bugfixes and added features.
  For a complete list take a look at the changelog located at:
  /usr/share/doc/packages/unbound/Changelog or
  https://www.nlnetlabs.nl/projects/unbound/download/

Some Noteworthy Changes:

• Removed DLV. The DLV has been decommisioned since unbound
  1.5.4 and has been advised to stop using it since. The use of
  dlv options displays a warning.
• Remove EDNS lame procedure, do not re-query without EDNS after
  timeout.
• Add DNS over HTTPS
• libunbound has been upgraded to major version 8

Security Fixes:

• CVE-2023-50387: DNSSEC verification complexity can be
  exploited to exhaust CPU resources and stall DNS resolvers. [bsc#1219823]
• CVE-2023-50868: NSEC3 closest encloser proof can exhaust CPU.
  [bsc#1219826]
• CVE-2022-30698: Novel ‘ghost domain names’ attack by
  introducing subdomain delegations. [bsc#1202033]
• CVE-2022-30699: Novel ‘ghost domain names’ attack by
  updating almost expired delegation information. [bsc#1202031]
• CVE-2022-3204: NRDelegation attack leads to uncontrolled
  resource consumption (Non-Responsive Delegation Attack). [bsc#1203643]

Packaging Changes:

• Use prefixes instead of sudo in unbound.service
• Remove no longer necessary BuildRequires: libfstrm-devel and
  libprotobuf-c-devel