Handle v6 rules for the mgmt bridge with nftables/iptables

[hellt]

• add v6 nftables
• remove v6 nftables
• add v6 iptables
• remove v6 iptables

[codecov]

Codecov Report

Attention: Patch coverage is 18.75000% with 65 lines in your changes missing coverage. Please review.

Project coverage is 51.85%. Comparing base (a75e770) to head (f880e38).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
runtime/docker/firewall/iptables/client.go	0.00%	54 Missing ⚠️
runtime/docker/firewall/nftables/client.go	57.69%	8 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2397      +/-   ##
==========================================
- Coverage   51.89%   51.85%   -0.05%     
==========================================
  Files         172      172              
  Lines       17316    17380      +64     
==========================================
+ Hits         8986     9012      +26     
- Misses       7386     7419      +33     
- Partials      944      949       +5     

Files with missing lines	Coverage Δ
runtime/docker/firewall.go	33.33% <ø> (ø)
runtime/docker/firewall/nftables/client.go	68.64% <57.69%> (-2.52%)	⬇️
runtime/docker/firewall/iptables/client.go	0.00% <0.00%> (ø)

... and 3 files with indirect coverage changes