rng-tools failed to install with "useradd: group rngd exists"

Issue

• When installing or updating rng-tools, it fails with the following error:

  $ sudo dnf install -y rng-tools
  Updating Subscription Management repositories.
  [...]
  Running transaction check
  Transaction check succeeded.
  Running transaction test
  Transaction test succeeded.
  Running transaction
    Preparing        :                                                                     1/1 
    Running scriptlet: rng-tools-6.14-4.git.b2b7934e.el8.x86_64                            1/1 
  useradd: group rngd exists - if you want to add this user to that group, use -g.
  error: %prein(rng-tools-6.14-4.git.b2b7934e.el8.x86_64) scriptlet failed, exit status 9
  
  Error in PREIN scriptlet in rpm package rng-tools
    Verifying        : rng-tools-6.14-4.git.b2b7934e.el8.x86_64                            1/1 
  Installed products updated.
  Uploading Tracer Profile
  
  Failed:
    rng-tools-6.14-4.git.b2b7934e.el8.x86_64                                                                                                                                          
  
  Error: Transaction failed