[TASK] change sg_mail dependency from >= 8 to >= 7

ext_emconf.php

@@ -18,7 +18,7 @@ $EM_CONF['sg_jobs'] = [
 				[
 					'typo3' => '10.4.0-11.5.99',
 					'php' => '7.3.0-8.1.99',
-					'sg_mail' => '>=8.0.0'
+					'sg_mail' => '>=7.0.0'
 				],
 			'conflicts' =>
 				[