nano: update to 5.9

2021.10.06 - GNU nano 5.9 "El manicomio ha decidido: mañana sol!"
• The extension of a filename is added to the name of a corresponding
  temporary file, so that spell checking a C file, for example, will
  check only the comments and strings (when using 'aspell').
• The process number is added to the name of an emergency save file,
  so that when multiple nanos die they will not fight over a filename.
• Undoing a cutting operation will restore an anchor that was located
  in the cut area to its original line.
• When using --locking, saving a new buffer will create a lock file.
• Syntax highlighting for YAML files has been added.

(nia)