Improve default cairo1 compiler error

[FabijanC]

Usage related changes

Several users have already run into getting errors like:

Declaring contract failed: [Errno 13] Permission denied: '/home/.../.cache/pypoetry/virtualenvs/starknet-dai-bridge-e9QJjikr-py3.9/lib/python3.9/site-packages/starkware/starknet/compiler/v1/bin/starknet-sierra-compile'

and

Compilation failed. Error: Invalid Sierra program.

This PR should improve the UX by providing a more meaningful error.

Development related changes

• Didn't add a test because it would require declaring a contract that was compiled with an alternative compiler version.
• In scripts/test.sh, increase maxprocesses from 8 to 10

Checklist:

• Applied formatting - ./scripts/format.sh
• No linter errors - ./scripts/lint.sh
• Performed code self-review
• Rebased to the last commit of the target branch (or merged it into my branch)
• Documented the changes
• Linked the issues which this PR resolves
• Updated the tests
• All tests are passing - ./scripts/test.sh