Removed need for generic_const_expr in bitmask

[jorgecarleitao]

Closes #223

[jorgecarleitao]

I am not sure if this is sufficient - I can't find the tests where we cover compiling under certain feature sets.

[workingjubilee]

Most of it is a simple feature-test on GitHub Actions.

You would need to remove the cfg from inside the tests.

You should also remove the feature entirely from the crate, as it is used nowhere else.

[jorgecarleitao]

I think that the feature is still in use in another part of the crate (module to_bytes).

[workingjubilee]

Ah, you are right actually. I forgot about that.
Also for some reason altering the ci.yaml stopped the tests from running entirely...

[jorgecarleitao]

Sorry, that was a bad commit. Fixed it.

[workingjubilee]

???
...I have no idea what's wrong here.

[jorgecarleitao]

Closing in favor of #238, since there is something going on with the CI in this one