Fix styling

Author: stefanzweifel

app/Actions/ShiftHeadingLevelInDocumentAction.php

@@ -47,11 +47,11 @@ public function execute(Document $document, int $baseHeadingLevel): Document
     /**
      * @param  array<Heading>  $headings
      */
-    public function findLowestHeadingLevel(array $headings): int|null
+    public function findLowestHeadingLevel(array $headings): ?int
     {
         return array_reduce(
             $headings,
-            function (int|null $level, Heading $heading) {
+            function (?int $level, Heading $heading) {
                 if ($level === null) {
                     return $heading->getLevel();
                 }

app/Commands/UpdateCommand.php

@@ -93,7 +93,7 @@ public function handle(AddReleaseNotesToChangelogAction $addReleaseNotesToChange
         }
     }
 
-    protected function getReleaseNotes(): null|string
+    protected function getReleaseNotes(): ?string
     {
         if ($this->option('parse-release-notes')) {
             return null;