Added shallow clone for submodules

[awesomekosm]

-will result in kb checkout instead of 180mb -if necessary to pull entire repo, can run git pull --unshallow

Description

Resolves #10218

PR checklist

• [ ] changelog provided | Pulling project by default will shallow clone resulting in a faster checkout
• [ ] development PR | not required because: not touched
• [ ] TF-PSA-Crypto PR | not required because: not touched
• [ ] framework PR | not required: not touched
• [ ] 3.6 PR | not required because:
• tests | not required because: nothing to test