[Ingest Manager] Agent Action are not correctly fetched during the checkin

[nchaulet]

Description

During the checkin we poll periodically for new action (like UNENROLL UPGRADE), to send them to the agent, this poll seems to not work as expected.

I suspect that KQL query to not be working as expected

kibana/x-pack/plugins/ingest_manager/server/services/agents/actions.ts

Lines 97 to 115 in 046345d

	const filter = nodeTypes.function.buildNode('and', [
	nodeTypes.function.buildNode(
	'not',
	nodeTypes.function.buildNode(
	'is',
	`${AGENT_ACTION_SAVED_OBJECT_TYPE}.attributes.sent_at`,
	'*'
	)
	),
	nodeTypes.function.buildNode(
	'range',
	`${AGENT_ACTION_SAVED_OBJECT_TYPE}.attributes.created_at`,
	{
	gte: timestamp,
	}
	),
	]);
	const res = await soClient.find<AgentActionSOAttributes>({
	type: AGENT_ACTION_SAVED_OBJECT_TYPE,

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)