Test by compiling sample contracts

Add two simple contracts (cairo0 and cairo1) and assert they can be compiled.

Can be done in this section of the shell script, perhaps after checking the versions:
https://github.com/Shard-Labs/cairo-cli-docker/blob/7cc3a832e99e28b9f136ab8909e42b03af780a15/build_and_push.sh#L27-L29

Look at the build_and_push.sh script around lines 27-29. Create two simple Cairo contracts (one cairo0, one cairo1) in the repository. Add a test step that uses the cairo-cli to compile them and verify the output. Check the existing script for how the CLI is invoked and ensure the test runs as part of the build process.

Written by the indexing model from the issue text.