Context

Protocol G has been injected (is in voting phase). The next protocol will use env-v3. This MR makes it so.

Note:

The development of the protocol and of the environment can now be done hand-in-hand.

Manually testing the MR

dune build @src/proto_alpha/check

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, the Development Version section of CHANGES.md for everything else).
Select suitable reviewers using the Reviewers field below.

Edited Jun 17, 2021 by Raphaël Proust