Hello, I have found a solution. There is a similar question here.
You can try:
sudo cp /var/cuda-repo-wsl-ubuntu-11-7-local/cuda-15CCF53C-keyring.gpg \
/usr/share/keyrings/cuda-archive-keyring.gpg
If there alreay is a cuda-archive-keyring.gpg in /usr/share/keyrings, do not forget to backup it first.