fix: pass 'permission' to train action

[bhearsum]

This is required for non-generic actions as of 11.0. I mucked this up when I did the upgrade. (See https://taskcluster-taskgraph.readthedocs.io/en/latest/reference/migrations.html.)

[bhearsum]

@ahal - can you advise here? The migration guide says:

If the argument isn’t present, or you are passing generic=False, then add a new argument called permission=<cb_name>, where <cb_name> is the value of whatever you are passing to the cb_name argument.

But we're getting:

[task 2024-09-23T17:54:31.899Z] E           Exception: Unknown callback: train. Known callbacks: rebuild-cached-tasks, retrigger-decision, retrigger-disabled, retrigger, rerun, retrigger-multiple, cancel, cancel-all, add-new-jobs

(Everything seems to work fine without this patch, eg: in #858 I managed to use the train action.)