Test against php 8.4 (#1066)

* Test against php 8.4

* Test against php 8.4

* Parameter is implicitly nullable via default value null

.github/workflows/run-static-analysis.yml

@@ -22,7 +22,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: [8.1, 8.2, 8.3]
+        php: [8.1, 8.2, 8.3, 8.4]
         laravel: [9.*, 10.*, 11.*]
         dependency-version: [prefer-stable]
         exclude:

.github/workflows/run-tests.yml

@@ -22,7 +22,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: [8.1, 8.2, 8.3]
+        php: [8.1, 8.2, 8.3, 8.4]
         laravel: ['9.*', '10.*', '11.*']
         dependency-version: [prefer-lowest, prefer-stable]
         exclude:

src/PDF.php

@@ -193,7 +193,7 @@ public function output(array $options = []): string
     /**
      * Save the PDF to a file
      */
-    public function save(string $filename, string $disk = null): self
+    public function save(string $filename, ?string $disk = null): self
     {
         $disk = $disk ?: $this->config->get('dompdf.disk');