Sorry for the inconvenience @koepnick - while searching across all repos has required being logged in for a long time, when we enhanced the search capabilities earlier in the 2023 we had to extend this to repos as well (see https://github.blog/changelog/2023-06-07-code-search-now-requires-login/).
This is primarily to ensure we can support the load for developers on GitHub and help protect the servers from being overwhelmed by anonymous requests from bots etc.
But this is true for literally anything that requires email verification to login with?
I think msft is scummy here but let's not pretend it's unusual that a company isn't going to help you if you can't access your email to verify your ownership.
If I lose access to my Gmail account and am unable to login to Amazon bc of that Amazon ain't going to help me.