Support ponos delegated auth

Depends https://gitlab.com/teklia/arkindex/backend/-/issues/1451
Depends https://gitlab.com/teklia/arkindex/api-client/-/issues/34
Refs https://redmine.teklia.com/issues/3228

The base worker must detect the environment variable ARKINDEX_TASK_TOKEN, and when it's set:

• use it as authentication token for the api token
• set Ponos as api scheme for the api client

changed milestone to %ML Prod - Next

added P2 label

changed the description

This should be closed I guess @schneider-y as you bumped the api client

Yes I made a few tests with the new version and it works fine (for now)

Done in !337 (merged)

closed