Mac os 27 will require unreleased Qt build (6.12 or 6.11.3)

Use on mac os 27 will need us to build with Qt 6.12 or 6.11.3

The next release 1.27.0 MUST wait for 6.12 or 6.11.3

Qt 6.11.3 is scheduled to be released September 24 Qt 6.12 will be released on September 30

Unless the 6.12 release continues to be pushed back we plan to use it for the 1.27.0 release.