debian: add polkit for trixie

[evadne]

• polkit is needed for systemd-networkd to set hostnames
• this operation can happen in an Incus container based on images:debian/trixie/cloud

$ incus create images:debian/trixie/cloud nettest

Then in container:

$ journalctl -u systemd-networkd
Jan 28 19:51:40 nettest systemd-networkd[189]: eth1: Gained IPv6LL
Jan 28 19:51:40 nettest systemd-networkd[189]: eth2: Gained IPv6LL
Jan 28 19:51:40 nettest systemd-networkd[189]: eth2: DHCPv4 address 192.168.254.28/24, gateway 192.168.254.1 acquired from 192.168.254.1
Jan 28 19:51:43 nettest systemd-networkd[189]: Could not set hostname: Access denied

Looks like polkit needs to be added back for trixie. Once the package is installed the error is gone.

IMHO this does need to be in place for both container and VM as in both scenarios one may have to configure network.

[spiritLHLS]

E: Unable to locate package polkit
Error: Failed to manage packages: Failed to install packages: exit status 100
time="2025-01-31T01:46:36Z" level=error msg="Failed running distrobuilder" err="Failed to manage packages: Failed to install packages: exit status 100"
time="2025-01-31T01:46:36Z" level=info msg="Removing cache directory"

It seems to be reporting errors on trixie, please check if there is a problem.