Use level 8 for PHPStan

Author: christeredvartsen

phpstan.neon

@@ -1,10 +1,14 @@
 parameters:
-	level: 6
+	level: 8
 	paths:
 		- src
 		- tests
 	ignoreErrors:
 		-
 			message: '#Method [a-zA-Z0-9\\_]+::test#'
 			identifier: missingType.iterableValue
-			path: tests
+			path: tests
+		-
+			message: '#Property [a-zA-Z0-9\\_]+::\$historyContainer#'
+			identifier: assign.propertyType
+			path: tests/Context/ApiContextTest.php