[CHANGES.md] replace bitwise-OR with logical-OR for expando declarations

[k-yle]

It seems like this example: f.x = f.x | init is not meant to be bitwise. I don't see any discussion in #1426 about this particular change, nor in the baselines that were accepted.

Strangely, this example doesn't actually work in Strada, regardless of whether it's a bitwise-OR with logical-OR. Playground link. So perhaps I'm missing something obvious...