submodules not cloning

unable to clone the submodules when cloning the project

```
git submodule update --init --recursive
Submodule 'cpython' (git@github.com:holzschu/cpython.git) registered for path 'cpython'
Cloning into '/Volumes/MSSD/a-shell/cpython'...
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
fatal: clone of 'git@github.com:holzschu/cpython.git' into submodule path '/Volumes/MSSD/a-shell/cpython' failed
Failed to clone 'cpython'. Retry scheduled
Cloning into '/Volumes/MSSD/a-shell/cpython'...
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
fatal: clone of 'git@github.com:holzschu/cpython.git' into submodule path '/Volumes/MSSD/a-shell/cpython' failed
Failed to clone 'cpython' a second time, aborting
```

Start by reproducing `git submodule update --init --recursive` and inspect how the `cpython` submodule is registered. Determine why cloning uses the SSH URL shown in the error and identify the project-supported access path. Done means a fresh recursive clone can obtain `cpython` without requiring unavailable repository permissions.

Written by the indexing model from the issue text.