Enable UnsafeUnstableInterface in local-runtime

[Szegoo]

For some reason UnsafeUnstableInterface is disabled in local-runtime, even though it is enabled in Shibuya.

This is pretty confusing and it took me quite some time to notice when I was doing e2e contract testing after testing the functionality manually on Shibuya.

This PR fixes that so that others do not run into this same issue 😅

[Dinonard]

I guess this is debatable - do you want to mimic Shibuya environment or Astar environment?
Neither is wrong or right, I guess.

Someone could equally raise an issue later that a contract worked on local but doesn't work on Astar since unstable interface isn't enabled.

[Szegoo]

Yes, there isn't really a 'correct' way to configure this. However, considering that the local-runtime doesn't closely resemble the Astar runtime and is meant for local testing, I think it would make more sense to have this enabled.

[Dinonard]

Yes, there isn't really a 'correct' way to configure this. However, considering that the local-runtime doesn't closely resemble the Astar runtime and is meant for local testing, I think it would make more sense to have this enabled.

We can merge it, sure.
If issue is mentioned or raised again, we'll have to consider a different approach.