Add Lint/DuplicatedKey to rubocop
Add Lint/DuplicatedKey to rubocop

Fixes openSUSE/osem#1437

AndrewKvalheim/osem,bear454/osem,differentreality/osem,openSUSE/osem,namangupta01/osem,rishabhptr/osem,SeaGL/osem,hennevogel/osem,bear454/osem,AndrewKvalheim/osem,kormoc/osem,hennevogel/osem,kormoc/osem,rishabhptr/osem,BelieveC/osem,differentreality/osem,hennevogel/osem,bear454/osem,kormoc/osem,openSUSE/osem,AndrewKvalheim/osem,SeaGL/osem,hennevogel/osem,differentreality/osem,BelieveC/osem,namangupta01/osem,BelieveC/osem,namangupta01/osem,BelieveC/osem,rishabhptr/osem,openSUSE/osem,kormoc/osem,differentreality/osem,rishabhptr/osem,bear454/osem,namangupta01/osem,SeaGL/osem