Declare missing properties in auth_plugin_anonymous

[daniil-berg]

As of PHP 8.2, assigning properties dynamically causes a deprecation warning. To reproduce this specific problem, just set the following in your config.php:

$CFG->debug = E_ALL;
$CFG->debugdisplay = 1;

And go to (for example) http://your.moodle/admin/settings.php?section=authsettinganonymous to see the notice:

Creation of dynamic property auth_plugin_anonymous::$FIRSTNAME is deprecated

This Patch simply adds the missing declarations.

Also, since PHP will coerce values to the declared types of the class properties, the intval call becomes unnecessary.

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Finally, unrelated to the previous issue, but too small for a separate PR:

There was a typo in the same constructor. Instead of role the desired config property is called assignrole. See line 97 here:

auth_anonymous/settings.php

Lines 96 to 103 in 90c5aba

	$settings->add(new admin_setting_configselect(
	'auth_anonymous/assignrole',
	get_string('role', 'auth_anonymous'),
	get_string('role_desc', 'auth_anonymous'),
	0,
	$roles,
	PARAM_INT
	));

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With these changes, using the aforementioned debug configuration will no longer produce warnings/error messages.