Support numeric exclusiveMinimum and exclusiveMaximum for 3.1

[charjr]

OpenAPI 3.1 follows the Json Schema from 2020:
exclusiveMaximum MUST be a number
exclusiveMinimum MUST be a number

To truly support the keywords there are 2 changes required:

• Allow for numeric values to be passed to exclusiveMaximum and exclusiveMinimum Support OpenAPI 3.1. ExclusiveMinimum and ExclusiveMaximum #23
• Do not use a boolean default if the OpenAPI is 3.1
  

  cebe-php-openapi/src/spec/Schema.php

  Lines 131 to 132 in 9ae960c

  	'exclusiveMinimum' => $this->hasPropertyValue('minimum') ? false : null,
  	'exclusiveMaximum' => $this->hasPropertyValue('maximum') ? false : null,

I am not sure how to go about providing a conditional default, that seems like a tricky task.