fix: make nullable parameter types explicit for PHP 8.1+ compatibility

src/Contracts/MetaTags/MetaInterface.php

@@ -29,7 +29,7 @@ public function setMetaFrom(object $object): self;
      *
      * @param positive-int|null $maxLength
      */
-    public function setTitle(string $title, int $maxLength = null): self;
+    public function setTitle(string $title, ?int $maxLength = null): self;
 
     /**
      * Prepend title part to default title

src/MetaTags/Concerns/ManageTitle.php

@@ -7,7 +7,7 @@
 
 trait ManageTitle
 {
-    public function setTitle(?string $title, int $maxLength = null): self
+    public function setTitle(?string $title, ?int $maxLength = null): self
     {
         $this->getTitle()->setTitle($this->cleanString($title), $maxLength);
 

src/Packages/Manager.php

@@ -23,7 +23,7 @@ public function register(PackageInterface $package): self
         return $this;
     }
 
-    public function create(string $name, Closure $callback = null): self
+    public function create(string $name, ?Closure $callback = null): self
     {
         $this->register($package = new Package($name));