Outdated compiled_programs dir should be removed before running transactions

[gabrielbosio]

This could be solved by automating the compiled_programs removal or by documenting it properly.

[JulianGCalderon]

I made a PR that updates the documentation, reminding users to remove the compiled_programs directory when updating Cairo Native.

I don't think we should automate its removal, as caching it saves a lot of execution time. This PR lambdaclass/cairo_native#981 will help reminding users to remove the cache directory.