Enable the YUL IR pipeline when building with optimisations

[Amxx]

Since 0.8.13, the YUL IR pipeline is no longer experimental.

This greatly impacts the compilation time when optimization is enabled (from ~20 to ~80sec on my machine), so most tests should continue to run on the non-optimized version.

[frangio]

Is viaIR: true the recommended setting now?

[Amxx]

From the 0.8.13 release note:

Furthermore, compiling via the new Yul IR pipeline is now considered production ready.

That doesn't really answer te question, but that is all I could find

[frangio]

Found this in the release announcement for 0.8.13:

The performance of the new pipeline is not yet always superior to the old one, but it can do much higher-level optimization across functions, so please try it out and give us feedback!

I don't think turning this on changes anything for us. If this is about the compiled artifacts we ship in the package, I wouldn't turn it on yet. If anything, when benchmarking we should be comparing both options and reporting odd results to the compiler team.

[Amxx]

I've also noticed that turning the IR pipeline cause some contract to not compile (some unspecified error showed up)

I don't think we should enable by default, but we should check our contract do compile with it ... and then do some gas comparaison