("The question of ripeness `goes to whether the district court had subject matter jurisdiction.") (quoting Greenbriar, 881 F.2d at 1573); see also Jacksonville Property Rights Ass 'n, Inc. v. City of Jacksonville, 635 F.3d 1266, 1276 (11th Cir. 2011) (concluding that when plaintiffs ask a court "to issue a declaration on an issue that