Fix phpstan errors

Author: ssnepenthe

src/FeatureCounter/NodeVisitor/ThrowExpressionFlaggingNodeVisitor.php

@@ -9,6 +9,9 @@
 use PhpParser\NodeVisitorAbstract;
 
 final class ThrowExpressionFlaggingNodeVisitor extends NodeVisitorAbstract {
+    /**
+     * @return null|int
+     */
     public function enterNode(Node $node) {
         if ($node instanceof Expression && $node->expr instanceof Throw_) {
             return NodeVisitor::DONT_TRAVERSE_CHILDREN;

src/FeatureCounter/ValueObject/FeatureCollector.php

@@ -26,7 +26,6 @@
 use PhpParser\Node\Stmt\ClassConst;
 use PhpParser\Node\Stmt\Declare_;
 use PhpParser\Node\Stmt\Enum_;
-use PhpParser\Node\Stmt\Expression;
 use PhpParser\Node\Stmt\Property;
 use PhpParser\Node\UnionType;
 use TomasVotruba\Lines\FeatureCounter\Enum\PhpVersion;