3.1 schema for top-level `servers` field does not match spec

[lmmarsano]

The schema says the value for servers is a single server object.

OpenAPI-Specification/schemas/v3.1/schema.yaml

Lines 14 to 15 in 6e5b27a

	servers:
	$ref: '#/$defs/server'

The spec says it's an array of those objects.

servers	[Server Object]	An array of Server Objects, which provide connectivity information to a target server. If the servers property is not provided, or is an empty array, the default value would be a Server Object with a url value of /.

[jdesrosiers]

Duplicate of #2526