Drop extreme sysctl tuning
No longer use legacy, unmaintained, and questionable tuning options.
Noteable:
- we no longer use iptables, but nftables
- we _do_ want IPv6 autoconfiguration
- we do _not_ want to tamper with swapping or nework logic unless
explicitly documented why
- non-local binding should _only_ be allowed on machines requiring it
Signed-off-by: Georg Pfuetzenreuter <georg.pfuetzenreuter@suse.com>