roles/common: Don't use iptables from buster-backports

This causes problems every time I re-run the Ansible tag because the
nightly apt security uses a different sources.list and the indexes
are then missing buster-backports. I could add a cache update to the
task, but actually I think the original bug I was trying to solve is
finally fixed, and I'm going to switch to nftables anyways.

roles/common/tasks/firewall_Debian.yml

@@ -1,10 +1,6 @@
 ---
 
 - block:
-  - name: Install iptables 1.8.3 on Debian Buster
-    when: ansible_distribution_major_version is version_compare('10', '==')
-    apt: pkg=iptables state=present default_release=buster-backports update_cache=yes cache_valid_time=3600
-
   - name: Install firewalld and deps
     when: ansible_distribution_major_version is version_compare('8', '>=')
     apt: pkg={{ item }} state=present