Add nix-serve

(cherry picked from commit 188c038897a5efb9becaefd8d814be67a2171449)
Signed-off-by: Domen Kožar <domen@dev.si>
nix: Update to 1.8

(cherry picked from commit e115bdecd8f6461080c9921919352117b13f44ae)
Signed-off-by: Domen Kožar <domen@dev.si>
nix-repl: Update

(cherry picked from commit bd0d1e836c92c197e384937cd906bdbdb058ffed)
Signed-off-by: Domen Kožar <domen@dev.si>