What

Removes lib_prod and --flag

Why

We want the latest version of the EVM node to be compatible with all "active" kernels.

The tests are now run on mainnet and latest kernel on each merge request, we just run it with lib_dev everywhere.

Document the interface of any function added or modified (see the coding guidelines)
Document any change to the user interface, including configuration parameters (see node configuration)
Provide automatic testing (see the testing guide).
For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
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