fix(hacks): remove redundancies in show_cursor

[ttytm]

I was constantly running into the issue of my cursor disappearing. To get it back, I had to manually(or via a dedicated au) re-set the gcr/guicursor setting.

Checking the code, I see you have some redundant checks for the same condition.
if M._guicursor and if not Util.is_exiting() are both check inside and outside of the scheduled function.

The removed double checks should also result in a minor improvement reducing load.

This fix can also help with the reports that people still experience #114.

[folke]

Those checks are not redundant and are there for a reason.

That code is also no longer used on newer Neovim versions.