Because the 11th january 2022 Github said:
This is the full brownout period where we’ll temporarily stop accepting the deprecated key and signature types, ciphers, MACs, and the unencrypted Git protocol. This will help clients discover any lingering use of older keys or old URLs.
So, You have to change the submodule origin, while users can perform the next command to avoid getting this error:
$ git config --global url."https://".insteadOf git://