Enhance end-to-end tests for IVC SNARK

[jpraynaud]

Why

The IVC SNARK end-to-end test only exists on a work in progress branch, which sacrifices the rest of the end-to-end matrix to run it and needs several hours per run. Nothing detects a regression of the SNARK path on main today.

What

Make the IVC SNARK end-to-end test mergeable and run it in the nightly tests, at a duration which does not need a dedicated matrix.

How

• Leanify feat: support IVC SNARK prover in e2e tests #3347: restore the end-to-end matrix, revert the temporary hacks
• Activate the recursive and non recursive SNARK minimal cases in the nightly end-to-end tests
• Reuse the circuit keys cache in the nodes of the end-to-end tests to remove the setup cost of each node start
• Reduce the epoch length and the run interval of the test to the shortest values that the proving time allows