Add macos-11.x to test matrix when no longer in preview

[heeler]

Use Case

Please provide a use case to help us understand your request in context

Make sure the module works on macos-11.0 when it becomes available.

Solution

Please describe your ideal solution

add macos-11.0 to the list of environments and that should do it.

Alternatives

Please describe any alternatives you've considered, even if you've dismissed them

Test on a macos-11.0 machine but that's only a stopgap measure.