patch 9.1.1114: enabling termguicolors automatically confuses users

patch 9.1.1114: enabling termguicolors automatically confuses users

Problem:  enabling termguicolors automatically confuses users. Since
          querying the terminal for the RGB flag happens asynchronously,
          enabling termguicolors is noticeable by users as the highlighting changes
          and is therefore unexpected.
          (after v9.1.1054)
Solution: comment out that part for now. We may need another way to
          enable this in the future.

fixes: #16539
fixes: #16568
fixes: #16649

Signed-off-by: Christian Brabandt <cb@256bit.org>