[fix] Replace "load" with "require_relative"

[rtfm98]

Replace "load" with "require_relative" as proposed by Discourse Dev Environment

Warning message

[{
	"resource": "/workspace/discourse/plugins/discourse-ratings/plugin.rb",
	"owner": "_generated_diagnostic_collection_name_#3",
	"code": "Discourse/Plugins/UseRequireRelative",
	"severity": 2,
	"message": "Discourse/Plugins/UseRequireRelative: Use `require_relative` instead of `load`.\n\nThis offense is not auto-correctable.\n",
	"source": "RuboCop",
	"startLineNumber": 90,
	"startColumn": 19,
	"endLineNumber": 90,
	"endColumn": 56,
	"origin": "extHost2"
}]

Change

Replaced load with require_relative

Tests

Tested in Discourse Dev Environment without problems