change_event_title_urls.php

<?php
// Put this in your theme's functions.php

// Add any title templates you want to modify.
$tribe_title_href_templates = [
	'events/v2/month/calendar-body/day/calendar-events/calendar-event/title',
];

// Loop through them!
foreach ( $tribe_title_href_templates as $hook_name ) {
  // We're using the tribe_template_html:{$hook_name} filter here, see https://theeventscalendar.com/knowledgebase/k/using-template-filters-and-actions/
	add_filter( "tribe_template_html:{$hook_name}", function( $html ) {
    // get the event website url.
		$url = tribe_get_event_website_url( tribe_get_event( get_the_ID() ) );

    // If no URL, bail (return unchanged HTML).
		if ( ! $url ) {
			return $html;
		}

    // Black magic (really, just look for an href="" and replace what's inside the quotes)
		$html = preg_replace(
			'/(href=")[^"]*(")/m',
			"$1{$url}$2",
			$html
		);

    // Return changed HTML.
		return $html;
	},
	10
 );
}

Worth noting that the search/replace is indiscriminate - so beware using this on templates that might contain other links!