Well robots.txt file cannot restrict the direct link to a file it just does not allow google to index .
Also it will take some time for google to recognize the robots.txt new rule and remove the unwanted links from its index .
https://support.google.com/webmasters/answer/9689846?hl=en
Hi its is requested to submit the url to google here : https://support.google.com/webmasters/answer/9689846?hl=en
Its the google which has cached the data , you need to contact them to remove the url .
HI you need to use this tool :
https://search.google.com/search-console/not-verified?original_url=/search-console/removals?utm_medium%3Dreferral%26utm_campaign%3D1663419&original_resource_id