More attacks by dump AI-bots

[Makarius]

In the past few days we've had more attacks on our servers, presumably by dumb 
AI-bots that cannot read robots.txt

This happens mainly in the late evening (Royal Bavarian Time).

Notable services that are compromised:

   https://isabelle.sketis.net/components
   https://isabelle.sketis.net/repos/isabelle
   https://isabelle.sketis.net/repos/isabelle-release


I am presently busy to sort out genuine problems on Isabelle2025-1 release 
candidates, and don't feel like participating in this non-sense out there. It 
requires more research what can be done about it, to return to sanity.


	Makarius