Should we relicense Xilem and Masonry to the dual MIT/Apache License?

[PoignardAzur]

There are a few reasons to do this:

• It's our default license.
• Some people are interested in having a maximally permissive license.
• Because Masonry is intended to be a foundational crate for most of the ecosystem, a maximally permissive license makes sense.

Any reason not to do this?

[DJMcNab]

Zulip discussion

The main reason to not want to is that a proportion of our code comes from Druid. That isn't in itself a problem, but it does make this task much more challenging, as we need to either determine how much of the Druid code we've kept, or also relicense Druid. I think that doing the latter is (remarkably) likely to be easier, and has greater advantage for the future. But it does make things a bit more complicated, and increases the likelihood of people being uncontactable.

See bevyengine/bevy#2373 and gfx-rs/wgpu#1473 for prior art