Perform V&V activities on RC 11.0.0-rc9

[samatstariongroup]

Perform the required V&V activities on 11.0.0-rc9

https://github.com/STARIONGROUP/COMET-IME-Community-Edition/releases/tag/11.0.0-rc9

Communicate via this ticket when 11.0.0-rc9 can be formally released

[belenatstariongroup]

Version 11.0.0-rc12 works as expected in single-user tests.