Remove usage of xml_set_object() function

The xml_set_object() function will be deprecated in PHP 8.4 as well as
passing non-callable strings to the xml_set_*_handler() functions.

Instead of using xml_set_object(), the string method names in
xml_set_element_handler() and xml_set_character_data_handler() should be
replaced with callables.

- https://wiki.php.net/rfc/deprecations_php_8_4#xml_set_object_and_xml_set_handler_with_string_method_names

Signed-off-by: Maurício Meneghini Fauth <mauricio@fauth.dev>

tcpdf.php

@@ -23170,14 +23170,12 @@ public function ImageSVG($file, $x=null, $y=null, $w=0, $h=0, $link='', $align='
 		$this->_out(sprintf('%F %F %F %F %F %F cm', $svgscale_x, 0, 0, $svgscale_y, ($e + $svgoffset_x), ($f + $svgoffset_y)));
 		// creates a new XML parser to be used by the other XML functions
 		$parser = xml_parser_create('UTF-8');
-		// the following function allows to use parser inside object
-		xml_set_object($parser, $this);
 		// disable case-folding for this XML parser
 		xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
 		// sets the element handler functions for the XML parser
-		xml_set_element_handler($parser, 'startSVGElementHandler', 'endSVGElementHandler');
+		xml_set_element_handler($parser, [$this, 'startSVGElementHandler'], [$this, 'endSVGElementHandler']);
 		// sets the character data handler function for the XML parser
-		xml_set_character_data_handler($parser, 'segSVGContentHandler');
+		xml_set_character_data_handler($parser, [$this, 'segSVGContentHandler']);
 		// start parsing an XML document
 		if (!xml_parse($parser, $svgdata)) {
 			$error_message = sprintf('SVG Error: %s at line %d', xml_error_string(xml_get_error_code($parser)), xml_get_current_line_number($parser));