CI Workflows

[hashcashier]

This PR introduces the following changes to the repository's github workflows:

1. Fixes for using the checkout action to include submodules during fetching.
2. Additions to the lint workflow for checking the solidity code using solhint.
3. Integration testing between the starter contracts and the example fibonnaci guest code.
4. End-to-end testing of remote proving on Bonsai.

[morgangibbs87]

• SSH key pair created
• Secret SSH_BPN_PRIVATE_KEY created in bonsai-foundry-template repo with private key
• Deploy Key ghrun_bonsai_foundry_template_to_bpn created in bpn repo with public key

Action ssh-agent will need to be used.