Proposal: Bump the minimum version of macOS for which we target JavaFX

[Martin Fox]

> My preference is to change the minimum version for Mac / x64 to be macOS 11.0, matching both the currently oldest version of macOS supported by Apple, and also unifying the minimum for the two chip architectures.

So no one else has to look this up:

The last security update for macOS 10.12 was in September of 2019. It was released in 2016.
The last security update for macOS 10.14 was in July of 2021. It was released in 2018.

macOS 11.0 was released in November of 2020. Support is likely to end this year.

11.0 could be installed on MacBooks from 2013 and desktops from 2014 (with some exceptions). If there’s a Mac out there that just can’t upgrade to 11.0 that machine is getting a little long in the tooth. FWIW I’m using an iMac from late 2017 and running the latest OS just fine.

I think ditching 10.x is the right move.

Martin