Merge pull request #11991 from dezgeg/pr-openssh-purity

openssh: Compile with '--with-pid-dir' to improve build purity

pkgs/tools/networking/openssh/default.nix

···
   # properly when cross building.
   configureFlags = [
     "--localstatedir=/var"
+    "--with-pid-dir=/run"
     "--with-mantype=man"
     "--with-libedit=yes"
     "--disable-strip"
···
     cp contrib/ssh-copy-id.1 $out/share/man/man1/
   '';
 
+  installTargets = [ "install-nokeys" ];
   installFlags = [
     "sysconfdir=\${out}/etc/ssh"
   ];