[ResponseOps][Task Manager] unrecognized tasks are not updated when mget task claimer is used

[pmuellr]

As part of the recent changes to x-pack/plugins/task_manager/server/task_claimers/strategy_mget.ts, we removed the code that marks tasks with removedTypes to Unrecognized.

You can see that code in a previous version of the module:

kibana/x-pack/plugins/task_manager/server/task_claimers/strategy_mget.ts

Lines 261 to 290 in 9653d7e

	// separate update for removed tasks; shouldn't happen often, so unlikely
	// a performance concern, and keeps the rest of the logic simpler
	let removedCount = 0;
	if (removedTasks.length > 0) {
	const tasksToRemove = Array.from(removedTasks);
	for (const task of tasksToRemove) {
	task.status = TaskStatus.Unrecognized;
	}
	// don't worry too much about errors, we'll get them next time
	try {
	const removeResults = await taskStore.bulkUpdate(tasksToRemove, {
	validate: false,
	excludeLargeFields: true,
	});
	for (const removeResult of removeResults) {
	if (isOk(removeResult)) {
	removedCount++;
	} else {
	const { id, type, error } = removeResult.error;
	logger.warn(
	`Error updating task ${id}:${type} to mark as unrecognized during claim: ${error.message}`,
	logMeta
	);
	}
	}
	} catch (err) {
	logger.warn(`Error updating tasks to mark as unrecognized during claim: ${err}`, logMeta);
	}
	}

Current thinking is that task manager should have a recurring task running, that can perform these updates. Task Manager's first recurring background task? \o/

These updates are not critical, they are more cleanliness, so we don't need to put the system through a lot of stress, often. Maybe once an hour, do a few thousand?

In theory we won't have version/OCC issues here, as TM will not be otherwise claiming these tasks.

Definition of Done

• Tasks part of the removedTypes convert to Unrecognized
• Tests

[elasticmachine]

Pinging @elastic/response-ops (Team:ResponseOps)

[mikecote]

I was able to get the functionality by doing the following within the mget claim strategy

      OneOfTaskTypes(
        'task.taskType',
        claimPartitions.unlimitedTypes.concat(Array.from(removedTypes))
      ),

This will merge in this PR => #196399 but it would be nice to have this part of a background task instead.