Fix grammar in user-facing exception (#3379)

Author: Wirone

rules/Arguments/Rector/ClassMethod/ArgumentAdderRector.php

@@ -212,7 +212,7 @@ private function fillGapBetweenWithDefaultValue(MethodCall | StaticCall $node, i
         for ($index = $lastPosition + 1; $index < $position; ++$index) {
             $param = $classMethod->params[$index];
             if (! $param->default instanceof Expr) {
-                throw new ShouldNotHappenException('Previous position does not has default value');
+                throw new ShouldNotHappenException('Previous position does not have default value');
             }
 
             $default = $this->nodePrinter->print($param->default);

src/NodeManipulator/PropertyManipulator.php

@@ -136,7 +136,7 @@ public function isPropertyChangeableExceptConstructor(Property | Param $property
     {
         $class = $this->betterNodeFinder->findParentType($propertyOrParam, Class_::class);
 
-        // does not has parent type ClassLike? Possibly parent is changed by other rule
+        // does not have parent type ClassLike? Possibly parent is changed by other rule
         if (! $class instanceof Class_) {
             return true;
         }