Useless systemd files in rescue/recovery system when no systemd is used

[jsmeix]

The contents of
skel/default/etc/systemd
skel/default/run/systemd
skel/default/usr/lib/systemd
skel/default/var/run/systemd
get copied into the rescue/recovery system
regardless if systemd is actually used or not, see
#1011 (comment)

This makes the rescue/recovery system bigger than
needed when no systemd is used.

I think I could enhance rescue/default/01_merge_skeletons.sh
to not copy systemd files into the rescue/recovery system
when no systemd is used.

On the other hand I wonder if nowadays this would provide
a real benefit for the users because nowadays systemd
is basically used on all systems.

[jsmeix]

According to
#1011 (comment)
not copying those systemd files into the rescue/recovery system
when no systemd is used could at most save about 236K
which is only about 0.067% of the 342M that the recovery system
has on my SLES12-SP2 test system, see
#1012 (comment)

With the same argument as in
#1012 (comment)

From my current point of view that is too little benefit
compared to the additional effort and compared to
the additional risk to mess up something subtle
in the recovery system...

I close this issue as "won't fix".