Media: Account for boolean false being returned by wp_getimagesize() when dealing with potentially invalid images in wp_read_image_metadata().

Prior to PHP 8.5 a boolean value was silently ignored when being passed to `list()`, but in PHP 8.5 and higher this now triggers a PHP warning. This change adds an appropriate guard condition.

Props swissspidy, adamsilverstein

Fixes #64295


git-svn-id: https://develop.svn.wordpress.org/trunk@61291 602fd350-edb4-49c9-b593-d223f7449a82

Author: johnbillion

src/wp-admin/includes/image.php

@@ -827,7 +827,13 @@ function wp_read_image_metadata( $file ) {
 		return false;
 	}
 
-	list( , , $image_type ) = wp_getimagesize( $file );
+	$image_size = wp_getimagesize( $file );
+
+	if ( false === $image_size ) {
+		return false;
+	}
+
+	list( , , $image_type ) = $image_size;
 
 	/*
 	 * EXIF contains a bunch of data we'll probably never need formatted in ways