Help plugins migration to eslint v9. #401

eslint v9 will have a few new deprecated api's, I replaced the ones used by the plugin itself in #400, but it was not an easy thing. This is to be tracking the changes related to eslint v9.

• Enhance rule no-deprecated-context-methods: Catch additional deprecated methods in no-deprecated-context-methods rule #398
• Add a new rule no-deprecated-sourcecode-methods
• Support flat config properties for test-case-property-ordering #402
• ...