Handle host vitals labels without `label_membership_type` in GitOps

[spalmesano0]

• Unpacked: Yes
• customer-pingali: Slack thread.
• @noahtalerman: Updated the docs: GitOps reference: No label_membership_type #39556
• @spalmesano0: When users create a host vitals label without specifying label_membership_type, like so:

- name: Engineering department
  description: Hosts used by engineers
  criteria:
    vital: end_user_idp_department
    value: Engineering

• @spalmesano0: A dynamic label with an empty query is created.

Some ways this could be handled:

1. Detect that criteria has vital set, and automatically assign label_membership_type: host_vitals.
2. Throw an error. Below is what happens when a manual label is created without label_membership_type: manual:

Error: 1 error occurred:
	* a SQL query or host vitals criteria is required for each non-manual label

[noahtalerman]

@rachaelshaw bug or feature request? I leaned feature request and updated the docs to clarify: #39556