Document WorkerRun GPU configuration

Refs https://redmine.teklia.com/issues/7534

Depends frontend#1455 (closed)

We need to update the documentation to reflect these changes around GPU configuration on worker runs:

• remove that part https://doc.arkindex.org/howto/run-process/#use-a-gpu
• add a new part on the same page in "configure workers" section https://doc.arkindex.org/howto/run-process/#configure-workers
  • update all screenshots for worker configuration as one more column appear
  • mention gpu checkbox when gpu is supported
  • and hardcoded rules (gpu required/disabled)